chore: upgrade libghostty and preserve terminal behavior (#3906)

63 files changed, 595 insertions, 391 deletions

diff --git a/vendor/libghostty-vt/src/font/Atlas.zig b/vendor/libghostty-vt/src/font/Atlas.zig
index d1206457..66e91c8f 100644
--- a/vendor/libghostty-vt/src/font/Atlas.zig
+++ b/vendor/libghostty-vt/src/font/Atlas.zig
@@ -32,7 +32,7 @@ data: []u8,
 size: u32 = 0,
 
 /// The nodes (rectangles) of available space.
-nodes: std.ArrayListUnmanaged(Node) = .{},
+nodes: std.ArrayList(Node) = .empty,
 
 /// The format of the texture data being written into the Atlas. This must be
 /// uniform for all textures in the Atlas. If you have some textures with
@@ -104,7 +104,7 @@ pub fn init(alloc: Allocator, size: u32, format: Format) Allocator.Error!Atlas {
     var result = Atlas{
         .data = try alloc.alloc(u8, size * size * format.depth()),
         .size = size,
-        .nodes = .{},
+        .nodes = .empty,
         .format = format,
     };
     errdefer result.deinit(alloc);
diff --git a/vendor/libghostty-vt/src/font/Collection.zig b/vendor/libghostty-vt/src/font/Collection.zig
index 5d7bfa51..6c646d9f 100644
--- a/vendor/libghostty-vt/src/font/Collection.zig
+++ b/vendor/libghostty-vt/src/font/Collection.zig
@@ -28,6 +28,7 @@ const Library = font.Library;
 const Metrics = font.Metrics;
 const Presentation = font.Presentation;
 const Style = font.Style;
+const SegmentedList = @import("../datastruct/segmented_list.zig").SegmentedList;
 
 const log = std.log.scoped(.font_collection);
 
@@ -662,7 +663,7 @@ fn scaleFactor(
     return primary_metric / face_metric;
 }
 
-const UpdateMetricsError = error{
+pub const UpdateMetricsError = error{
     CannotLoadPrimaryFont,
 };
 
@@ -694,7 +695,7 @@ pub fn updateMetrics(self: *Collection) UpdateMetricsError!void {
 ///
 /// WARNING: We cannot use any prealloc yet for the segmented list because
 /// the collection is copied around by value and pointers aren't stable.
-const StyleArray = std.EnumArray(Style, std.SegmentedList(EntryOrAlias, 0));
+const StyleArray = std.EnumArray(Style, SegmentedList(EntryOrAlias, 0));
 
 /// Load options are used to configure all the details a Collection
 /// needs to load deferred faces.
@@ -894,7 +895,7 @@ pub const Index = packed struct(Index.Backing) {
 
     /// The number of bits we use for the index.
     const idx_bits = backing_bits - @typeInfo(@typeInfo(Style).@"enum".tag_type).int.bits;
-    pub const IndexInt = @Type(.{ .int = .{ .signedness = .unsigned, .bits = idx_bits } });
+    pub const IndexInt = @Int(.unsigned, idx_bits);
 
     /// The special-case fonts that we support.
     pub const Special = enum(IndexInt) {
diff --git a/vendor/libghostty-vt/src/font/DeferredFace.zig b/vendor/libghostty-vt/src/font/DeferredFace.zig
index 425f3c28..9a8124c9 100644
--- a/vendor/libghostty-vt/src/font/DeferredFace.zig
+++ b/vendor/libghostty-vt/src/font/DeferredFace.zig
@@ -184,7 +184,8 @@ pub fn name(self: DeferredFace, buf: []u8) ![]const u8 {
         .coretext_harfbuzz,
         .coretext_noshape,
         => if (self.ct) |ct| {
-            const display_name = ct.font.copyDisplayName();
+            const display_name = ct.font.copyDisplayName() orelse
+                return self.familyName(buf);
             return display_name.cstringPtr(.utf8) orelse unsupported: {
                 // "NULL if the internal storage of theString does not allow
                 // this to be returned efficiently." In this case, we need
diff --git a/vendor/libghostty-vt/src/font/Metrics.zig b/vendor/libghostty-vt/src/font/Metrics.zig
index 60a300b0..36cfe009 100644
--- a/vendor/libghostty-vt/src/font/Metrics.zig
+++ b/vendor/libghostty-vt/src/font/Metrics.zig
@@ -589,23 +589,21 @@ pub const Modifier = union(enum) {
 /// Key is an enum of all the available metrics keys.
 pub const Key = key: {
     const field_infos = std.meta.fields(Metrics);
-    var enumFields: [field_infos.len]std.builtin.Type.EnumField = undefined;
+    var names: [field_infos.len][]const u8 = undefined;
+    var raw_values: [field_infos.len]comptime_int = undefined;
     var count: usize = 0;
-    for (field_infos, 0..) |field, i| {
+    for (field_infos, &names, &raw_values, 0..) |field, *name, *raw, i| {
         if (field.type != u32 and field.type != i32 and field.type != f64) continue;
-        enumFields[i] = .{ .name = field.name, .value = i };
+        name.* = field.name;
+        raw.* = i;
         count += 1;
     }
 
-    var decls = [_]std.builtin.Type.Declaration{};
-    break :key @Type(.{
-        .@"enum" = .{
-            .tag_type = std.math.IntFittingRange(0, count - 1),
-            .fields = enumFields[0..count],
-            .decls = &decls,
-            .is_exhaustive = true,
-        },
-    });
+    const TagInt = std.math.IntFittingRange(0, count - 1);
+    var values: [count]TagInt = undefined;
+    for (raw_values, &values) |raw, *v| v.* = raw;
+
+    break :key @Enum(TagInt, .exhaustive, names[0..count], &values);
 };
 
 // NOTE: This is purposely not pub because we want to force outside callers
diff --git a/vendor/libghostty-vt/src/font/SharedGrid.zig b/vendor/libghostty-vt/src/font/SharedGrid.zig
index 18870aab..92cf0500 100644
--- a/vendor/libghostty-vt/src/font/SharedGrid.zig
+++ b/vendor/libghostty-vt/src/font/SharedGrid.zig
@@ -34,6 +34,7 @@ const Metrics = font.Metrics;
 const Presentation = font.Presentation;
 const Style = font.Style;
 const RenderOptions = font.Glyph.RenderOptions;
+const global = @import("../global.zig");
 
 const log = std.log.scoped(.font_shared_grid);
 
@@ -60,7 +61,7 @@ metrics: Metrics,
 /// this directly if they need to i.e. access the atlas directly. Because
 /// callers can use this lock directly, maintainers need to be extra careful
 /// to review call sites to ensure they are using the lock correctly.
-lock: std.Thread.RwLock,
+lock: std.Io.RwLock,
 
 pub const init_tw = tripwire.module(enum {
     codepoints_capacity,
@@ -68,6 +69,8 @@ pub const init_tw = tripwire.module(enum {
     reload_metrics,
 }, init);
 
+pub const InitError = std.mem.Allocator.Error || Collection.UpdateMetricsError;
+
 /// Initialize the grid.
 ///
 /// The resolver must have a collection that supports deferred loading
@@ -80,7 +83,7 @@ pub const init_tw = tripwire.module(enum {
 pub fn init(
     alloc: Allocator,
     resolver: CodepointResolver,
-) !SharedGrid {
+) InitError!SharedGrid {
     const tw = init_tw;
 
     // We need to support loading options since we use the size data
@@ -95,7 +98,7 @@ pub fn init(
         .resolver = resolver,
         .atlas_grayscale = atlas_grayscale,
         .atlas_color = atlas_color,
-        .lock = .{},
+        .lock = .init,
         .metrics = undefined, // Loaded below
     };
 
@@ -162,14 +165,14 @@ pub fn getIndex(
     // Fast path: the cache has the value. This is almost always true and
     // only requires a read lock.
     {
-        self.lock.lockShared();
-        defer self.lock.unlockShared();
+        self.lock.lockSharedUncancelable(global.io());
+        defer self.lock.unlockShared(global.io());
         if (self.codepoints.get(key)) |v| return v;
     }
 
     // Slow path: we need to search this codepoint
-    self.lock.lock();
-    defer self.lock.unlock();
+    self.lock.lockUncancelable(global.io());
+    defer self.lock.unlock(global.io());
 
     // Try to get it, if it is now in the cache another thread beat us to it.
     const gop = try self.codepoints.getOrPut(alloc, key);
@@ -201,8 +204,8 @@ pub fn hasCodepoint(
     cp: u32,
     p: ?Presentation,
 ) bool {
-    self.lock.lockShared();
-    defer self.lock.unlockShared();
+    self.lock.lockSharedUncancelable(global.io());
+    defer self.lock.unlockShared(global.io());
     return self.resolver.collection.hasCodepoint(
         idx,
         cp,
@@ -236,8 +239,8 @@ pub fn renderCodepoint(
 
     // Get the glyph for the font
     const glyph_index = glyph_index: {
-        self.lock.lockShared();
-        defer self.lock.unlockShared();
+        self.lock.lockSharedUncancelable(global.io());
+        defer self.lock.unlockShared(global.io());
         const face = try self.resolver.collection.getFace(index);
         break :glyph_index face.glyphIndex(cp) orelse return null;
     };
@@ -250,6 +253,127 @@ pub const renderGlyph_tw = tripwire.module(enum {
     get_presentation,
 }, renderGlyph);
 
+// FIXME: This gets a massive manual error set for now because there is an
+// equally massive call stack in the get_presentation tracepoint. This should
+// be consolidated into something better ASAP.
+pub const RenderGlyphError = error{
+    ArrayTooLarge,
+    AtlasFull,
+    BadArgument,
+    BbxTooBig,
+    BitmapHandlingError,
+    CMapTableMissing,
+    CannotOpenResource,
+    CannotOpenStream,
+    CannotRenderGlyph,
+    CodeOverflow,
+    CorruptedFontGlyphs,
+    CorruptedFontHeader,
+    CouldNotFindContext,
+    DebugOpCode,
+    DeferredLoadingUnavailable,
+    DivideByZero,
+    ENDFInExecStream,
+    ExecutionTooLong,
+    FontHasNoFile,
+    FontPathCantDecode,
+    FontconfigFailed,
+    FontconfigNoId,
+    FontconfigNoMatch,
+    FontconfigTypeMismatch,
+    GlyphResizeFailed,
+    HarfbuzzFailed,
+    HmtxTableMissing,
+    HorizHeaderMissing,
+    Ignore,
+    IndexOutOfBounds,
+    InvalidArgument,
+    InvalidAtlasFormat,
+    InvalidCacheHandle,
+    InvalidCharMapFormat,
+    InvalidCharMapHandle,
+    InvalidCharacterCode,
+    InvalidCodeRange,
+    InvalidComposite,
+    InvalidDriverHandle,
+    InvalidFaceHandle,
+    InvalidFileFormat,
+    InvalidFrameOperation,
+    InvalidFrameRead,
+    InvalidGlyphFormat,
+    InvalidGlyphIndex,
+    InvalidHandle,
+    InvalidHeight,
+    InvalidHorizMetrics,
+    InvalidLibraryHandle,
+    InvalidMatrix,
+    InvalidOffset,
+    InvalidOpcode,
+    InvalidOutline,
+    InvalidPPem,
+    InvalidPixelSize,
+    InvalidPostTable,
+    InvalidPostTableFormat,
+    InvalidReference,
+    InvalidSVGTable,
+    InvalidSizeHandle,
+    InvalidSlotHandle,
+    InvalidState,
+    InvalidStreamHandle,
+    InvalidStreamOperation,
+    InvalidStreamRead,
+    InvalidStreamSeek,
+    InvalidStreamSkip,
+    InvalidTable,
+    InvalidVersion,
+    InvalidVertMetrics,
+    InvalidWidth,
+    LocationsMissing,
+    LowerModuleVersion,
+    MathError,
+    MissingBbxField,
+    MissingCharsField,
+    MissingEncodingField,
+    MissingFontField,
+    MissingFontboundingboxField,
+    MissingModule,
+    MissingProperty,
+    MissingSizeField,
+    MissingStartcharField,
+    MissingStartfontField,
+    NameTableMissing,
+    NestedDEFS,
+    NestedFrameAccess,
+    NoCurrentPoint,
+    NoUnicodeGlyphName,
+    OutOfMemory,
+    PathNotClosed,
+    PixelSourceNotPreMultiplied,
+    PostTableMissing,
+    RasterCorrupted,
+    RasterNegativeHeight,
+    RasterOverflow,
+    RasterUninitialized,
+    SpecialHasNoFace,
+    StackOverflow,
+    StackUnderflow,
+    Syntax,
+    TableMissing,
+    TooFewArguments,
+    TooManyCaches,
+    TooManyDrivers,
+    TooManyExtensions,
+    TooManyFunctionDefs,
+    TooManyHints,
+    TooManyInstructionDefs,
+    UnimplementedFeature,
+    UnknownFileFormat,
+    UnknownFreetypeError,
+    UnlistedObject,
+    UnsupportedGlyphFormat,
+    WrongAtlas,
+};
+
 /// Render a glyph index. This automatically determines the correct texture
 /// atlas to use and caches the result.
 pub fn renderGlyph(
@@ -258,7 +382,7 @@ pub fn renderGlyph(
     index: Collection.Index,
     glyph_index: u32,
     opts: RenderOptions,
-) !Render {
+) RenderGlyphError!Render {
     const tw = renderGlyph_tw;
 
     const key: GlyphKey = .{ .index = index, .glyph = glyph_index, .opts = opts };
@@ -266,14 +390,14 @@ pub fn renderGlyph(
     // Fast path: the cache has the value. This is almost always true and
     // only requires a read lock.
     {
-        self.lock.lockShared();
-        defer self.lock.unlockShared();
+        self.lock.lockSharedUncancelable(global.io());
+        defer self.lock.unlockShared(global.io());
         if (self.glyphs.get(key)) |v| return v;
     }
 
     // Slow path: we need to search this codepoint
-    self.lock.lock();
-    defer self.lock.unlock();
+    self.lock.lockUncancelable(global.io());
+    defer self.lock.unlock(global.io());
 
     const gop = try self.glyphs.getOrPut(alloc, key);
     if (gop.found_existing) return gop.value_ptr.*;
@@ -468,8 +592,8 @@ test "renderGlyph error after cache insert rolls back cache entry" {
 
     // Get the glyph index for 'A'
     const glyph_index = glyph_index: {
-        grid.lock.lockShared();
-        defer grid.lock.unlockShared();
+        grid.lock.lockSharedUncancelable(testing.io);
+        defer grid.lock.unlockShared(testing.io);
         const face = try grid.resolver.collection.getFace(idx);
         break :glyph_index face.glyphIndex('A').?;
     };
diff --git a/vendor/libghostty-vt/src/font/SharedGridSet.zig b/vendor/libghostty-vt/src/font/SharedGridSet.zig
index 9d8148bd..dc7d8dd7 100644
--- a/vendor/libghostty-vt/src/font/SharedGridSet.zig
+++ b/vendor/libghostty-vt/src/font/SharedGridSet.zig
@@ -28,6 +28,7 @@ const SharedGrid = font.SharedGrid;
 const discovery = @import("discovery.zig");
 const configpkg = @import("../config.zig");
 const Config = configpkg.Config;
+const global = @import("../global.zig");
 
 const log = std.log.scoped(.font_shared_grid_set);
 
@@ -44,7 +45,7 @@ font_lib: Library,
 font_discover: ?Discover = null,
 
 /// Lock to protect multi-threaded access to the map.
-lock: std.Thread.Mutex = .{},
+lock: std.Io.Mutex = .init,
 
 pub const InitError = Library.InitError;
 
@@ -79,8 +80,8 @@ pub fn deinit(self: *SharedGridSet) void {
 
 /// Returns the number of cached grids.
 pub fn count(self: *SharedGridSet) usize {
-    self.lock.lock();
-    defer self.lock.unlock();
+    self.lock.lockUncancelable(global.io());
+    defer self.lock.unlock(global.io());
     return self.map.count();
 }
 
@@ -100,8 +101,8 @@ pub fn ref(
     var key = try Key.init(self.alloc, config, font_size);
     errdefer key.deinit();
 
-    self.lock.lock();
-    defer self.lock.unlock();
+    self.lock.lockUncancelable(global.io());
+    defer self.lock.unlock(global.io());
 
     const gop = try self.map.getOrPut(self.alloc, key);
     if (gop.found_existing) {
@@ -339,6 +340,24 @@ fn collection(
     // specifying a font-family for emoji.
     if (comptime builtin.target.os.tag.isDarwin() and Discover != void) apple_emoji: {
         const disco = try self.discover() orelse break :apple_emoji;
+
+        // Fast path: we know the exact name of the font we want so we
+        // can look it up directly, which is sometimes significantly faster than
+        // full discovery (e.g. CoreText).
+        if (@hasDecl(Discover, "discoverExactFamily")) {
+            if (try disco.discoverExactFamily(
+                "Apple Color Emoji",
+            )) |face| {
+                _ = try c.addDeferred(self.alloc, face, .{
+                    .style = .regular,
+                    .fallback = true,
+                    // No size adjustment for emojis.
+                    .size_adjustment = .none,
+                });
+                break :apple_emoji;
+            }
+        }
+
         var disco_it = try disco.discover(self.alloc, .{
             .family = "Apple Color Emoji",
         });
@@ -392,8 +411,8 @@ fn collection(
 /// Decrement the ref count for the given key. If the ref count is zero,
 /// the grid will be deinitialized and removed from the map.j:w
 pub fn deref(self: *SharedGridSet, key: Key) void {
-    self.lock.lock();
-    defer self.lock.unlock();
+    self.lock.lockUncancelable(global.io());
+    defer self.lock.unlock(global.io());
 
     const entry = self.map.getEntry(key) orelse return;
     assert(entry.value_ptr.ref >= 1);
diff --git a/vendor/libghostty-vt/src/font/discovery.zig b/vendor/libghostty-vt/src/font/discovery.zig
index b945aa01..1847693a 100644
--- a/vendor/libghostty-vt/src/font/discovery.zig
+++ b/vendor/libghostty-vt/src/font/discovery.zig
@@ -12,6 +12,7 @@ const Face = @import("main.zig").Face;
 const Library = @import("main.zig").Library;
 const Presentation = @import("main.zig").Presentation;
 const Variation = @import("main.zig").face.Variation;
+const global = @import("../global.zig");
 
 const log = std.log.scoped(.discovery);
 
@@ -349,6 +350,22 @@ pub const CoreText = struct {
         _ = self;
     }
 
+    /// Warm up the system font registry.
+    ///
+    /// The first CoreText query in a process initializes the system font
+    /// database, which takes multiple milliseconds, while subsequent
+    /// queries are microseconds.
+    pub fn warmup() void {
+        const name = macos.foundation.String.createWithBytes(
+            "AppleColorEmoji",
+            .utf8,
+            false,
+        ) catch return;
+        defer name.release();
+        const ct_font = macos.text.Font.createWithName(name, 12) catch return;
+        ct_font.release();
+    }
+
     /// Discover fonts from a descriptor. This returns an iterator that can
     /// be used to build up the deferred fonts.
     pub fn discover(self: *const CoreText, alloc: Allocator, desc: Descriptor) !DiscoverIterator {
@@ -382,6 +399,54 @@ pub const CoreText = struct {
         };
     }
 
+    /// Discover a font by its exact name (family, full, or PostScript
+    /// name). This is significantly faster than `discover` because it
+    /// avoids the system-wide font matching that CTFontCollection does
+    /// (which takes multiple milliseconds). This should be preferred
+    /// when the desired font is known exactly, e.g. system fonts such
+    /// as Apple Color Emoji.
+    ///
+    /// Returns null if no font with this exact family name exists;
+    /// CoreText fallback fonts are never returned.
+    pub fn discoverExactFamily(
+        self: *const CoreText,
+        family: []const u8,
+    ) !?DeferredFace {
+        _ = self;
+
+        const family_str = try macos.foundation.String.createWithBytes(
+            family,
+            .utf8,
+            false,
+        );
+        defer family_str.release();
+
+        // Create our font. We need a size to initialize it so we use size
+        // 12 but we will alter the size later (same as DiscoverIterator).
+        const ct_font = try macos.text.Font.createWithName(family_str, 12);
+
+        // CTFontCreateWithName never returns null: if the requested font
+        // isn't installed it returns a substitute font. Verify we got
+        // the family we asked for, otherwise report not found.
+        const found: bool = found: {
+            const actual = ct_font.copyFamilyName();
+            defer actual.release();
+            var buf: [256]u8 = undefined;
+            const actual_slice = actual.cstring(&buf, .utf8) orelse
+                break :found false;
+            break :found std.mem.eql(u8, actual_slice, family);
+        };
+        if (!found) {
+            ct_font.release();
+            return null;
+        }
+
+        return .{ .ct = .{
+            .font = ct_font,
+            .variations = &.{},
+        } };
+    }
+
     pub fn discoverFallback(
         self: *const CoreText,
         alloc: Allocator,
@@ -942,15 +1007,15 @@ pub const Windows = struct {
         desc: Descriptor,
         variations: []const Variation,
         state: State,
-        dir: ?std.fs.Dir,
-        iter: ?std.fs.Dir.Iterator,
+        dir: ?std.Io.Dir,
+        iter: ?std.Io.Dir.Iterator,
         system_path: ?[:0]const u8,
         user_path: ?[:0]const u8,
 
         const State = enum { system, user, done };
 
         pub fn deinit(self: *DiscoverIterator) void {
-            if (self.dir) |*d| d.close();
+            if (self.dir) |*d| d.close(global.io());
             if (self.system_path) |p| self.alloc.free(p);
             if (self.user_path) |p| self.alloc.free(p);
             self.* = undefined;
@@ -967,7 +1032,8 @@ pub const Windows = struct {
                                 continue;
                             };
                             self.system_path = path;
-                            self.dir = std.fs.openDirAbsoluteZ(
+                            self.dir = std.Io.Dir.openDirAbsolute(
+                                global.io(),
                                 path,
                                 .{ .iterate = true },
                             ) catch {
@@ -982,7 +1048,8 @@ pub const Windows = struct {
                                 continue;
                             };
                             self.user_path = path;
-                            self.dir = std.fs.openDirAbsoluteZ(
+                            self.dir = std.Io.Dir.openDirAbsolute(
+                                global.io(),
                                 path,
                                 .{ .iterate = true },
                             ) catch {
@@ -995,9 +1062,9 @@ pub const Windows = struct {
                     }
                 }
 
-                const entry = (self.iter.?.next() catch null) orelse {
+                const entry = (self.iter.?.next(global.io()) catch null) orelse {
                     // Finished this directory; advance state.
-                    if (self.dir) |*d| d.close();
+                    if (self.dir) |*d| d.close(global.io());
                     self.dir = null;
                     self.iter = null;
                     self.state = switch (self.state) {
@@ -1020,7 +1087,7 @@ pub const Windows = struct {
         /// Windows install but we just skip the directory rather than
         /// falling back to a hardcoded drive letter.
         fn systemFontsPath(self: *DiscoverIterator) ?[:0]const u8 {
-            const systemroot = std.process.getEnvVarOwned(
+            const systemroot = global.environ().getAlloc(
                 self.alloc,
                 "SYSTEMROOT",
             ) catch return null;
@@ -1034,7 +1101,7 @@ pub const Windows = struct {
         }
 
         fn userFontsPath(self: *DiscoverIterator) ?[:0]const u8 {
-            const local_appdata = std.process.getEnvVarOwned(
+            const local_appdata = global.environ().getAlloc(
                 self.alloc,
                 "LOCALAPPDATA",
             ) catch return null;
diff --git a/vendor/libghostty-vt/src/font/face/coretext.zig b/vendor/libghostty-vt/src/font/face/coretext.zig
index cd8bc7d8..4b2af153 100644
--- a/vendor/libghostty-vt/src/font/face/coretext.zig
+++ b/vendor/libghostty-vt/src/font/face/coretext.zig
@@ -926,6 +926,7 @@ const ColorState = struct {
             const svg = opentype.SVG.init(ptr[0..len]) catch |err| {
                 return switch (err) {
                     error.EndOfStream,
+                    error.ReadFailed,
                     error.SVGVersionNotSupported,
                     => error.InvalidSVGTable,
                 };
diff --git a/vendor/libghostty-vt/src/font/face/freetype.zig b/vendor/libghostty-vt/src/font/face/freetype.zig
index d04fe180..14a378e5 100644
--- a/vendor/libghostty-vt/src/font/face/freetype.zig
+++ b/vendor/libghostty-vt/src/font/face/freetype.zig
@@ -18,6 +18,7 @@ const Library = font.Library;
 const opentype = @import("../opentype.zig");
 const quirks = @import("../../quirks.zig");
 const config = @import("../../config.zig");
+const global = @import("../../global.zig");
 
 const F26Dot6 = opentype.sfnt.F26Dot6;
 
@@ -41,7 +42,7 @@ pub const Face = struct {
     ///
     /// This means that anywhere where `self.face.loadGlyph`
     /// is called, this mutex must be held.
-    ft_mutex: *std.Thread.Mutex,
+    ft_mutex: *std.Io.Mutex,
 
     /// Harfbuzz font corresponding to this face.
     hb_font: harfbuzz.Font,
@@ -68,8 +69,8 @@ pub const Face = struct {
         index: i32,
         opts: font.face.Options,
     ) !Face {
-        lib.mutex.lock();
-        defer lib.mutex.unlock();
+        lib.mutex.lockUncancelable(global.io());
+        defer lib.mutex.unlock(global.io());
         const face = try lib.lib.initFace(path, index);
         errdefer face.deinit();
         return try initFace(lib, face, opts);
@@ -81,8 +82,8 @@ pub const Face = struct {
         source: [:0]const u8,
         opts: font.face.Options,
     ) !Face {
-        lib.mutex.lock();
-        defer lib.mutex.unlock();
+        lib.mutex.lockUncancelable(global.io());
+        defer lib.mutex.unlock(global.io());
         const face = try lib.lib.initMemoryFace(source, 0);
         errdefer face.deinit();
         return try initFace(lib, face, opts);
@@ -99,9 +100,9 @@ pub const Face = struct {
         var hb_font = try harfbuzz.freetype.createFont(face.handle);
         errdefer hb_font.destroy();
 
-        const ft_mutex = try lib.alloc.create(std.Thread.Mutex);
+        const ft_mutex = try lib.alloc.create(std.Io.Mutex);
         errdefer lib.alloc.destroy(ft_mutex);
-        ft_mutex.* = .{};
+        ft_mutex.* = .init;
 
         var result: Face = .{
             .lib = lib,
@@ -142,8 +143,8 @@ pub const Face = struct {
     pub fn deinit(self: *Face) void {
         self.lib.alloc.destroy(self.ft_mutex);
         {
-            self.lib.mutex.lock();
-            defer self.lib.mutex.unlock();
+            self.lib.mutex.lockUncancelable(global.io());
+            defer self.lib.mutex.unlock(global.io());
 
             self.face.deinit();
         }
@@ -330,8 +331,8 @@ pub const Face = struct {
 
     /// Returns true if the given glyph ID is colorized.
     pub fn isColorGlyph(self: *const Face, glyph_id: u32) bool {
-        self.ft_mutex.lock();
-        defer self.ft_mutex.unlock();
+        self.ft_mutex.lockUncancelable(global.io());
+        defer self.ft_mutex.unlock(global.io());
 
         // Load the glyph and see what pixel mode it renders with.
         // All modes other than BGRA are non-color.
@@ -429,8 +430,8 @@ pub const Face = struct {
         glyph_index: u32,
         opts: font.Glyph.RenderOptions,
     ) !Glyph {
-        self.ft_mutex.lock();
-        defer self.ft_mutex.unlock();
+        self.ft_mutex.lockUncancelable(global.io());
+        defer self.ft_mutex.unlock(global.io());
 
         // Load the glyph.
         try self.face.loadGlyph(glyph_index, self.glyphLoadFlags(opts.constraint.doesAnything()));
@@ -541,7 +542,7 @@ pub const Face = struct {
                     else
                         0.0;
 
-                const outline = &glyph.*.outline;
+                const outline: *freetype.c.FT_Outline = &glyph.*.outline;
                 for (outline.points[0..@intCast(outline.n_points)]) |*p| {
                     // Convert to f64 for processing
                     var px = f26dot6ToF64(p.x);
@@ -971,8 +972,8 @@ pub const Face = struct {
         // the metrics provided by FreeType, and set ascii_height to null as
         // it's optional.
         const cell_width: f64, const ascii_height: ?f64 = measurements: {
-            self.ft_mutex.lock();
-            defer self.ft_mutex.unlock();
+            self.ft_mutex.lockUncancelable(global.io());
+            defer self.ft_mutex.unlock(global.io());
 
             var max: f64 = 0.0;
             var top: f64 = 0.0;
@@ -1024,8 +1025,8 @@ pub const Face = struct {
 
             break :heights .{
                 cap: {
-                    self.ft_mutex.lock();
-                    defer self.ft_mutex.unlock();
+                    self.ft_mutex.lockUncancelable(global.io());
+                    defer self.ft_mutex.unlock(global.io());
                     if (face.getCharIndex('H')) |glyph_index| {
                         if (face.loadGlyph(glyph_index, self.glyphLoadFlags(false))) {
                             break :cap getGlyphSize(face.handle.*.glyph).height;
@@ -1034,8 +1035,8 @@ pub const Face = struct {
                     break :cap null;
                 },
                 ex: {
-                    self.ft_mutex.lock();
-                    defer self.ft_mutex.unlock();
+                    self.ft_mutex.lockUncancelable(global.io());
+                    defer self.ft_mutex.unlock(global.io());
                     if (face.getCharIndex('x')) |glyph_index| {
                         if (face.loadGlyph(glyph_index, self.glyphLoadFlags(false))) {
                             break :ex getGlyphSize(face.handle.*.glyph).height;
@@ -1048,8 +1049,8 @@ pub const Face = struct {
 
         // Measure "水" (CJK water ideograph, U+6C34) for our ic width.
         const ic_width: ?f64 = ic_width: {
-            self.ft_mutex.lock();
-            defer self.ft_mutex.unlock();
+            self.ft_mutex.lockUncancelable(global.io());
+            defer self.ft_mutex.unlock(global.io());
 
             const glyph = face.getCharIndex('水') orelse break :ic_width null;
 
diff --git a/vendor/libghostty-vt/src/font/glyf_rasterize.zig b/vendor/libghostty-vt/src/font/glyf_rasterize.zig
index f321214b..f288ff0a 100644
--- a/vendor/libghostty-vt/src/font/glyf_rasterize.zig
+++ b/vendor/libghostty-vt/src/font/glyf_rasterize.zig
@@ -99,14 +99,16 @@ pub fn rasterize(
     // bitmap just like an empty outline.
     if (bounds.width() == 0 or bounds.height() == 0) return Bitmap.initEmpty(alloc, width, height);
 
-    // Build the surface we'll draw on. This is a simple alpha8 drawing.
-    var sfc: z2d.Surface = try .init(
+    // Build the surface directly over the bitmap we'll return.
+    const data = try alloc.alloc(u8, @as(usize, width) * @as(usize, height));
+    errdefer alloc.free(data);
+    var sfc: z2d.Surface = .initBuffer(
         .image_surface_alpha8,
-        alloc,
+        null,
+        std.mem.bytesAsSlice(z2d.pixel.Alpha8, data),
         @intCast(width),
         @intCast(height),
     );
-    defer sfc.deinit(alloc);
 
     var path: z2d.Path = .empty;
     defer path.deinit(alloc);
@@ -133,7 +135,7 @@ pub fn rasterize(
     return .{
         .width = width,
         .height = height,
-        .data = try alloc.dupe(u8, std.mem.sliceAsBytes(sfc.image_surface_alpha8.buf)),
+        .data = data,
     };
 }
 
diff --git a/vendor/libghostty-vt/src/font/glyf_rasterize_png_test.zig b/vendor/libghostty-vt/src/font/glyf_rasterize_png_test.zig
index e8ad70fd..881c0ed9 100644
--- a/vendor/libghostty-vt/src/font/glyf_rasterize_png_test.zig
+++ b/vendor/libghostty-vt/src/font/glyf_rasterize_png_test.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const Allocator = std.mem.Allocator;
 const wuffs = @import("wuffs");
 const z2d = @import("z2d");
+const compat_file = @import("../lib/compat/file.zig");
 
 const glyf_rasterize = @import("glyf_rasterize.zig");
 const glyf = @import("opentype/glyf.zig");
@@ -107,37 +108,38 @@ fn drawCellBoxes(atlas: *z2d.Surface, y: usize, cell_width: usize, cell_height:
 /// `glyf_rasterize_diff.png`, where red is reference-only coverage and green is
 /// newly generated coverage. Returns true when a difference was found.
 fn diffAtlas(
+    io: std.Io,
     alloc: Allocator,
     atlas: *z2d.Surface,
     generated_path: []const u8,
 ) !bool {
     const ref_path = "src/font/testdata/glyf_rasterize.png";
 
-    const generated_file = try std.fs.openFileAbsolute(generated_path, .{ .mode = .read_only });
-    defer generated_file.close();
-    const generated_bytes = try generated_file.readToEndAlloc(alloc, std.math.maxInt(usize));
+    const generated_file = try std.Io.Dir.openFileAbsolute(io, generated_path, .{ .mode = .read_only });
+    defer generated_file.close(io);
+    const generated_bytes = try compat_file.readToEndAlloc(generated_file, alloc, std.math.maxInt(usize));
     defer alloc.free(generated_bytes);
 
-    const cwd_absolute = try std.fs.cwd().realpathAlloc(alloc, ".");
+    const cwd_absolute = try std.Io.Dir.cwd().realPathFileAlloc(io, ".", alloc);
     defer alloc.free(cwd_absolute);
 
-    const ref_file = std.fs.cwd().openFile(ref_path, .{ .mode = .read_only }) catch |err| {
+    const ref_file = std.Io.Dir.cwd().openFile(io, ref_path, .{ .mode = .read_only }) catch |err| {
         log.err("Can't open reference file {s}: {}", .{ ref_path, err });
 
         const test_path = try std.fmt.allocPrint(alloc, "{s}/glyf_rasterize_test.png", .{cwd_absolute});
         defer alloc.free(test_path);
-        try std.fs.copyFileAbsolute(generated_path, test_path, .{});
+        try std.Io.Dir.copyFileAbsolute(generated_path, test_path, io, .{});
         return true;
     };
-    defer ref_file.close();
-    const ref_bytes = try ref_file.readToEndAlloc(alloc, std.math.maxInt(usize));
+    defer ref_file.close(io);
+    const ref_bytes = try compat_file.readToEndAlloc(ref_file, alloc, std.math.maxInt(usize));
     defer alloc.free(ref_bytes);
 
     if (std.mem.eql(u8, generated_bytes, ref_bytes)) return false;
 
     const test_path = try std.fmt.allocPrint(alloc, "{s}/glyf_rasterize_test.png", .{cwd_absolute});
     defer alloc.free(test_path);
-    try std.fs.copyFileAbsolute(generated_path, test_path, .{});
+    try std.Io.Dir.copyFileAbsolute(generated_path, test_path, io, .{});
 
     const ref_rgba = try wuffs.png.decode(alloc, ref_bytes);
     defer alloc.free(ref_rgba.data);
@@ -185,7 +187,7 @@ fn diffAtlas(
     }
 
     const diff_path = "./glyf_rasterize_diff.png";
-    try z2d.png_exporter.writeToPNGFile(diff, diff_path, .{});
+    try z2d.png_exporter.writeToPNGFile(io, diff, diff_path, .{});
     log.err(
         "glyf rasterize visual output differs from reference: test={s}, reference={s}, diff={s}",
         .{ test_path, ref_path, diff_path },
@@ -290,12 +292,12 @@ test "glyf_rasterize: bubbletea glyph protocol examples match reference image" {
 
     var dir = testing.tmpDir(.{});
     defer dir.cleanup();
-    const tmp_dir = try dir.dir.realpathAlloc(alloc, ".");
+    const tmp_dir = try dir.dir.realPathFileAlloc(testing.io, ".", alloc);
     defer alloc.free(tmp_dir);
 
     const generated_path = try std.fmt.allocPrint(alloc, "{s}/glyf_rasterize.png", .{tmp_dir});
     defer alloc.free(generated_path);
-    try z2d.png_exporter.writeToPNGFile(atlas, generated_path, .{});
+    try z2d.png_exporter.writeToPNGFile(testing.io, atlas, generated_path, .{});
 
-    try testing.expect(!try diffAtlas(alloc, &atlas, generated_path));
+    try testing.expect(!try diffAtlas(testing.io, alloc, &atlas, generated_path));
 }
diff --git a/vendor/libghostty-vt/src/font/library.zig b/vendor/libghostty-vt/src/font/library.zig
index 56946343..49c2e880 100644
--- a/vendor/libghostty-vt/src/font/library.zig
+++ b/vendor/libghostty-vt/src/font/library.zig
@@ -30,7 +30,7 @@ pub const FreetypeLibrary = struct {
 
     /// Mutex to be held any time the library is
     /// being used to create or destroy a face.
-    mutex: *std.Thread.Mutex,
+    mutex: *std.Io.Mutex,
 
     pub const InitError = freetype.Error || Allocator.Error;
 
@@ -38,8 +38,8 @@ pub const FreetypeLibrary = struct {
         const lib = try freetype.Library.init();
         errdefer lib.deinit();
 
-        const mutex = try alloc.create(std.Thread.Mutex);
-        mutex.* = .{};
+        const mutex = try alloc.create(std.Io.Mutex);
+        mutex.* = .init;
 
         return Library{ .lib = lib, .alloc = alloc, .mutex = mutex };
     }
diff --git a/vendor/libghostty-vt/src/font/opentype/glyf.zig b/vendor/libghostty-vt/src/font/opentype/glyf.zig
index 912b5fe8..d95b7ece 100644
--- a/vendor/libghostty-vt/src/font/opentype/glyf.zig
+++ b/vendor/libghostty-vt/src/font/opentype/glyf.zig
@@ -1,6 +1,7 @@
 const std = @import("std");
 const Allocator = std.mem.Allocator;
 const sfnt = @import("sfnt.zig");
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 /// Glyph Data Table
 ///
@@ -245,11 +246,10 @@ pub const Glyf = struct {
         ///
         /// The lifetime of this struct, then, is the same as the
         /// lifetime of the data that is used to initialize it.
-        pub fn init(data: []const u8) error{EndOfStream}!Entry {
-            var fbs = std.io.fixedBufferStream(data);
-            const reader = fbs.reader();
-            const header = try reader.readStructEndian(Header, .big);
-            return .{ .header = header, .data = data[fbs.pos..] };
+        pub fn init(data: []const u8) std.Io.Reader.Error!Entry {
+            var reader: std.Io.Reader = .fixed(data);
+            const header = try compat_reader.readStructEndian(&reader, Header, .big);
+            return .{ .header = header, .data = data[@sizeOf(Header)..] };
         }
 
         /// Identifies what type (simple or composite) of entry this is.
@@ -262,10 +262,6 @@ pub const Glyf = struct {
 
         /// Errors that can be returned from `Entry.size()`.
         pub const SizeError = error{
-            /// The entry's data wasn't large enough, ran
-            /// out of bytes before we were done reading.
-            EndOfStream,
-
             /// The entry contains hinting instructions,
             /// which we don't currently support.
             InstructionsNotSupported,
@@ -283,7 +279,7 @@ pub const Glyf = struct {
             /// This entry defines points past the index determined
             /// by the final element of the endPtsOfContours array.
             TooManyPoints,
-        };
+        } || std.Io.Reader.Error;
 
         /// Errors that can be returned from `Entry.decode()`.
         pub const DecodeError = SizeError || Allocator.Error || error{
@@ -299,8 +295,7 @@ pub const Glyf = struct {
         /// NOTE: Currently produces errors when given composite glyphs
         ///       or any glyphs that have hinting instructions included.
         pub fn size(self: Entry) SizeError!usize {
-            var fbs = std.io.fixedBufferStream(self.data);
-            const reader = fbs.reader();
+            var reader: std.Io.Reader = .fixed(self.data);
             switch (self.entryType()) {
                 // https://learn.microsoft.com/en-us/typography/opentype/spec/glyf#simple-glyph-description
                 .simple => {
@@ -329,7 +324,7 @@ pub const Glyf = struct {
                     // of each contour, in increasing numeric order.
                     var max_point_index: isize = -1;
                     for (0..num_contours) |_| {
-                        const index = try reader.readInt(sfnt.uint16, .big);
+                        const index = try compat_reader.readerInt(&reader, sfnt.uint16, .big);
                         // The endpoints are supposed to monotonically increase.
                         if (index <= max_point_index) return error.EndPointsOutOfOrder;
                         max_point_index = index;
@@ -342,7 +337,7 @@ pub const Glyf = struct {
                     // If instructionLength is zero, no instructions
                     // are present for this glyph, and this field is
                     // followed directly by the flags field.
-                    const instructions_length = try reader.readInt(sfnt.uint16, .big);
+                    const instructions_length = try compat_reader.readerInt(&reader, sfnt.uint16, .big);
 
                     // Since we don't have code that validates instruction
                     // byte code, we just reject all glyphs that contain any.
@@ -373,7 +368,7 @@ pub const Glyf = struct {
                     var x_coords_len: usize = 0;
                     var y_coords_len: usize = 0;
                     while (i <= max_point_index) : (i += 1) {
-                        const flag: SimpleFlags = @bitCast(try reader.readByte());
+                        const flag: SimpleFlags = @bitCast(try compat_reader.readByte(&reader));
 
                         // Determine how many bytes the x and y coordinates will
                         // be represented with in the corresponding arrays, add
@@ -393,7 +388,7 @@ pub const Glyf = struct {
                             // that count, and the x_coords_len and y_coords_len
                             // must be increased by the correct number of bytes
                             // as well.
-                            const repeat_count: usize = try reader.readByte();
+                            const repeat_count: usize = try compat_reader.readByte(&reader);
                             i += repeat_count;
                             x_coords_len += repeat_count * flag.xBytes();
                             y_coords_len += repeat_count * flag.yBytes();
@@ -415,7 +410,7 @@ pub const Glyf = struct {
                     // We determined the length of this section (in bytes)
                     // above while processing the flags, so that we can just
                     // skip that many bytes to validate this field.
-                    try reader.skipBytes(x_coords_len, .{});
+                    try compat_reader.readSkipBytes(&reader, x_coords_len);
 
                     // uint8 or int16 yCoordinates[variable]
                     //
@@ -426,7 +421,7 @@ pub const Glyf = struct {
                     // We determined the length of this section (in bytes)
                     // above while processing the flags, so that we can just
                     // skip that many bytes to validate this field.
-                    try reader.skipBytes(y_coords_len, .{});
+                    try compat_reader.readSkipBytes(&reader, y_coords_len);
                 },
 
                 .composite => {
@@ -441,7 +436,7 @@ pub const Glyf = struct {
             }
 
             // No issues found, the glyf entry is valid, return its length.
-            return @sizeOf(Header) + fbs.pos;
+            return @sizeOf(Header) + reader.seek;
         }
 
         /// Decode this simple glyph entry into an owned outline.
@@ -455,8 +450,7 @@ pub const Glyf = struct {
                 .composite => return error.CompositeNotSupported,
             }
 
-            var fbs = std.io.fixedBufferStream(self.data);
-            const reader = fbs.reader();
+            var reader: std.Io.Reader = .fixed(self.data);
 
             // A zero-contour glyph may be header-only. See size for the
             // reason for the hardcoded 2 here.
@@ -473,7 +467,7 @@ pub const Glyf = struct {
             // If we have no contours, then the only possible remaining
             // field is instructionLength. Instructions are not supported.
             if (num_contours == 0) {
-                const instructions_length = try reader.readInt(sfnt.uint16, .big);
+                const instructions_length = try compat_reader.readerInt(&reader, sfnt.uint16, .big);
                 if (instructions_length > 0) return error.InstructionsNotSupported;
                 return .{ .points = &.{}, .contours = end_points };
             }
@@ -488,7 +482,7 @@ pub const Glyf = struct {
                 // with the valid index. The final endpoint tells us our point
                 // count, since endpoints are stored as inclusive point indices.
                 for (0..end_points.len) |i| {
-                    const index = try reader.readInt(sfnt.uint16, .big);
+                    const index = try compat_reader.readerInt(&reader, sfnt.uint16, .big);
                     if (index <= prev_end_point) return error.EndPointsOutOfOrder;
                     prev_end_point = index;
                     end_points[i] = index;
@@ -499,7 +493,7 @@ pub const Glyf = struct {
             };
 
             // Instructions are not supported.
-            const instructions_length = try reader.readInt(sfnt.uint16, .big);
+            const instructions_length = try compat_reader.readerInt(&reader, sfnt.uint16, .big);
             if (instructions_length > 0) return error.InstructionsNotSupported;
 
             // Allocate our points right away even though the next entries
@@ -522,12 +516,12 @@ pub const Glyf = struct {
             {
                 var point_i: usize = 0;
                 while (point_i < point_count) {
-                    const flag: SimpleFlags = @bitCast(try reader.readByte());
+                    const flag: SimpleFlags = @bitCast(try compat_reader.readByte(&reader));
                     flags[point_i] = flag;
                     point_i += 1;
 
                     if (flag.repeat) {
-                        const repeat_count: usize = try reader.readByte();
+                        const repeat_count: usize = try compat_reader.readByte(&reader);
                         if (point_i + repeat_count > point_count) return error.TooManyPoints;
 
                         for (0..repeat_count) |_| {
@@ -543,11 +537,11 @@ pub const Glyf = struct {
             for (flags, points) |flag, *point| {
                 const dx: i32 = if (flag.x_short) short: {
                     break :short if (flag.x_repeat_or_sign)
-                        @as(i32, try reader.readByte())
+                        @as(i32, try compat_reader.readByte(&reader))
                     else
-                        -@as(i32, try reader.readByte());
+                        -@as(i32, try compat_reader.readByte(&reader));
                 } else if (!flag.x_repeat_or_sign)
-                    @as(i32, try reader.readInt(sfnt.int16, .big))
+                    @as(i32, try compat_reader.readerInt(&reader, sfnt.int16, .big))
                 else
                     0;
 
@@ -564,11 +558,11 @@ pub const Glyf = struct {
             for (flags, points) |flag, *point| {
                 const dy: i32 = if (flag.y_short) short: {
                     break :short if (flag.y_repeat_or_sign)
-                        @as(i32, try reader.readByte())
+                        @as(i32, try compat_reader.readByte(&reader))
                     else
-                        -@as(i32, try reader.readByte());
+                        -@as(i32, try compat_reader.readByte(&reader));
                 } else if (!flag.y_repeat_or_sign)
-                    @as(i32, try reader.readInt(sfnt.int16, .big))
+                    @as(i32, try compat_reader.readerInt(&reader, sfnt.int16, .big))
                 else
                     0;
 
@@ -599,7 +593,7 @@ pub const Glyf = struct {
     }
 
     /// Retrieve the entry at the provided offset.
-    pub fn entry(self: Glyf, index: usize) error{EndOfStream}!Entry {
+    pub fn entry(self: Glyf, index: usize) std.Io.Reader.Error!Entry {
         return try Entry.init(self.data[index..]);
     }
 };
diff --git a/vendor/libghostty-vt/src/font/opentype/head.zig b/vendor/libghostty-vt/src/font/opentype/head.zig
index 38284d9c..009fd144 100644
--- a/vendor/libghostty-vt/src/font/opentype/head.zig
+++ b/vendor/libghostty-vt/src/font/opentype/head.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const sfnt = @import("sfnt.zig");
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 /// Font Header Table
 ///
@@ -134,10 +135,9 @@ pub const Head = extern struct {
     glyphDataFormat: sfnt.int16 align(1),
 
     /// Parse the table from raw data.
-    pub fn init(data: []const u8) error{EndOfStream}!Head {
-        var fbs = std.io.fixedBufferStream(data);
-        const reader = fbs.reader();
-        return try reader.readStructEndian(Head, .big);
+    pub fn init(data: []const u8) std.Io.Reader.Error!Head {
+        var reader: std.Io.Reader = .fixed(data);
+        return try compat_reader.readStructEndian(&reader, Head, .big);
     }
 };
 
diff --git a/vendor/libghostty-vt/src/font/opentype/hhea.zig b/vendor/libghostty-vt/src/font/opentype/hhea.zig
index b2b3f3e2..7ad77054 100644
--- a/vendor/libghostty-vt/src/font/opentype/hhea.zig
+++ b/vendor/libghostty-vt/src/font/opentype/hhea.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const sfnt = @import("sfnt.zig");
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 /// Horizontal Header Table
 ///
@@ -71,10 +72,8 @@ pub const Hhea = extern struct {
 
     /// Parse the table from raw data.
     pub fn init(data: []const u8) !Hhea {
-        var fbs = std.io.fixedBufferStream(data);
-        const reader = fbs.reader();
-
-        return try reader.readStructEndian(Hhea, .big);
+        var reader: std.Io.Reader = .fixed(data);
+        return try compat_reader.readStructEndian(&reader, Hhea, .big);
     }
 };
 
diff --git a/vendor/libghostty-vt/src/font/opentype/os2.zig b/vendor/libghostty-vt/src/font/opentype/os2.zig
index 1cd11f35..5bb0b42b 100644
--- a/vendor/libghostty-vt/src/font/opentype/os2.zig
+++ b/vendor/libghostty-vt/src/font/opentype/os2.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const sfnt = @import("sfnt.zig");
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 pub const FSSelection = packed struct(sfnt.uint16) {
     /// Font contains italic or oblique glyphs, otherwise they are upright.
@@ -348,21 +349,17 @@ pub const OS2 = struct {
     usUpperOpticalPointSize: ?u16 = null,
 
     /// Parse the table from raw data.
-    pub fn init(data: []const u8) error{
-        EndOfStream,
-        OS2VersionNotSupported,
-    }!OS2 {
-        var fbs = std.io.fixedBufferStream(data);
-        const reader = fbs.reader();
+    pub fn init(data: []const u8) (error{OS2VersionNotSupported} || std.Io.Reader.Error)!OS2 {
+        var reader: std.Io.Reader = .fixed(data);
 
-        const version = try reader.readInt(sfnt.uint16, .big);
+        const version = try compat_reader.readerInt(&reader, sfnt.uint16, .big);
 
         // Return to the start, cause the version is part of the struct.
-        try fbs.seekTo(0);
+        reader.seek = 0;
 
         switch (version) {
             5 => {
-                const table = try reader.readStructEndian(OS2v5, .big);
+                const table = try compat_reader.readStructEndian(&reader, OS2v5, .big);
                 return .{
                     .version = table.version,
                     .xAvgCharWidth = table.xAvgCharWidth,
@@ -406,7 +403,7 @@ pub const OS2 = struct {
                 };
             },
             4, 3, 2 => {
-                const table = try reader.readStructEndian(OS2v4_3_2, .big);
+                const table = try compat_reader.readStructEndian(&reader, OS2v4_3_2, .big);
                 return .{
                     .version = table.version,
                     .xAvgCharWidth = table.xAvgCharWidth,
@@ -448,7 +445,7 @@ pub const OS2 = struct {
                 };
             },
             1 => {
-                const table = try reader.readStructEndian(OS2v1, .big);
+                const table = try compat_reader.readStructEndian(&reader, OS2v1, .big);
                 return .{
                     .version = table.version,
                     .xAvgCharWidth = table.xAvgCharWidth,
@@ -485,7 +482,7 @@ pub const OS2 = struct {
                 };
             },
             0 => {
-                const table = try reader.readStructEndian(OS2v0, .big);
+                const table = try compat_reader.readStructEndian(&reader, OS2v0, .big);
                 return .{
                     .version = table.version,
                     .xAvgCharWidth = table.xAvgCharWidth,
diff --git a/vendor/libghostty-vt/src/font/opentype/post.zig b/vendor/libghostty-vt/src/font/opentype/post.zig
index 8031a0a4..776bf8a3 100644
--- a/vendor/libghostty-vt/src/font/opentype/post.zig
+++ b/vendor/libghostty-vt/src/font/opentype/post.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const sfnt = @import("sfnt.zig");
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 /// PostScript Table
 ///
@@ -46,10 +47,9 @@ pub const Post = extern struct {
     maxMemType1: sfnt.uint32 align(1),
 
     /// Parse the table from raw data.
-    pub fn init(data: []const u8) error{EndOfStream}!Post {
-        var fbs = std.io.fixedBufferStream(data);
-        const reader = fbs.reader();
-        return try reader.readStructEndian(Post, .big);
+    pub fn init(data: []const u8) std.Io.Reader.Error!Post {
+        var reader: std.Io.Reader = .fixed(data);
+        return try compat_reader.readStructEndian(&reader, Post, .big);
     }
 };
 
diff --git a/vendor/libghostty-vt/src/font/opentype/sfnt.zig b/vendor/libghostty-vt/src/font/opentype/sfnt.zig
index 55a9a0bd..8b182e69 100644
--- a/vendor/libghostty-vt/src/font/opentype/sfnt.zig
+++ b/vendor/libghostty-vt/src/font/opentype/sfnt.zig
@@ -235,8 +235,7 @@ pub const SFNT = struct {
     /// Parse a font from raw data. The struct will keep a
     /// reference to `data` and use it for future operations.
     pub fn init(data: []const u8, alloc: Allocator) !SFNT {
-        var fbs = std.io.fixedBufferStream(data);
-        const reader = fbs.reader();
+        var reader: std.Io.Reader = .fixed(data);
 
         // SFNT files use big endian, if our native endian is
         // not big we'll need to byte swap the values we read.
@@ -244,7 +243,7 @@ pub const SFNT = struct {
 
         var directory: Directory = undefined;
 
-        try reader.readNoEof(std.mem.asBytes(&directory.offset));
+        try reader.readSliceAll(std.mem.asBytes(&directory.offset));
         if (byte_swap) std.mem.byteSwapAllFields(
             Directory.OffsetSubtable,
             &directory.offset,
@@ -252,7 +251,7 @@ pub const SFNT = struct {
 
         directory.records = try alloc.alloc(Directory.TableRecord, directory.offset.num_tables);
 
-        try reader.readNoEof(std.mem.sliceAsBytes(directory.records));
+        try reader.readSliceAll(std.mem.sliceAsBytes(directory.records));
         if (byte_swap) for (directory.records) |*record| {
             std.mem.byteSwapAllFields(
                 Directory.TableRecord,
diff --git a/vendor/libghostty-vt/src/font/opentype/svg.zig b/vendor/libghostty-vt/src/font/opentype/svg.zig
index b4d9ccaa..9115fe62 100644
--- a/vendor/libghostty-vt/src/font/opentype/svg.zig
+++ b/vendor/libghostty-vt/src/font/opentype/svg.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const font = @import("../main.zig");
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 /// SVG glyphs description table.
 ///
@@ -21,27 +22,24 @@ pub const SVG = struct {
     /// All records in the table.
     records: []const [12]u8,
 
-    pub fn init(data: []const u8) error{
-        EndOfStream,
-        SVGVersionNotSupported,
-    }!SVG {
-        var fbs = std.io.fixedBufferStream(data);
-        const reader = fbs.reader();
+    pub fn init(data: []const u8) (error{SVGVersionNotSupported} || std.Io.Reader.Error)!SVG {
+        var reader: std.Io.Reader = .fixed(data);
 
         // Version
-        if (try reader.readInt(u16, .big) != 0) {
+        if (try compat_reader.readerInt(&reader, u16, .big) != 0) {
             return error.SVGVersionNotSupported;
         }
 
         // Offset
-        const offset = try reader.readInt(u32, .big);
+        const offset = try compat_reader.readerInt(&reader, u32, .big);
 
         // Seek to the offset to get our document list
-        try fbs.seekTo(offset);
+        if (offset > data.len) return error.EndOfStream;
+        reader.seek = offset;
 
         // Get our document records along with the start/end glyph range.
-        const len = try reader.readInt(u16, .big);
-        const records: [*]const [12]u8 = @ptrCast(data[try fbs.getPos()..]);
+        const len = try compat_reader.readerInt(&reader, u16, .big);
+        const records: [*]const [12]u8 = @ptrCast(data[reader.seek..]);
         const start_range = try glyphRange(&records[0]);
         const end_range = if (len == 1) start_range else try glyphRange(&records[(len - 1)]);
 
@@ -84,11 +82,10 @@ pub const SVG = struct {
     }
 
     fn glyphRange(record: []const u8) !struct { u16, u16 } {
-        var fbs = std.io.fixedBufferStream(record);
-        const reader = fbs.reader();
+        var reader: std.Io.Reader = .fixed(record);
         return .{
-            try reader.readInt(u16, .big),
-            try reader.readInt(u16, .big),
+            try compat_reader.readerInt(&reader, u16, .big),
+            try compat_reader.readerInt(&reader, u16, .big),
         };
     }
 };
@@ -112,3 +109,13 @@ test "SVG" {
     try testing.expectEqual(11482, svg.end_glyph_id);
     try testing.expect(svg.hasGlyph(11482));
 }
+
+test "SVG document list offset past end" {
+    const testing = std.testing;
+    const table = [_]u8{
+        0, 0, // Version
+        0, 0, 0, 7, // Document list offset, one byte past end
+    };
+
+    try testing.expectError(error.EndOfStream, SVG.init(&table));
+}
diff --git a/vendor/libghostty-vt/src/font/shaper/coretext.zig b/vendor/libghostty-vt/src/font/shaper/coretext.zig
index 8a9374bd..5172744d 100644
--- a/vendor/libghostty-vt/src/font/shaper/coretext.zig
+++ b/vendor/libghostty-vt/src/font/shaper/coretext.zig
@@ -20,6 +20,7 @@ const SharedGrid = font.SharedGrid;
 const Style = font.Style;
 const Presentation = font.Presentation;
 const CFReleaseThread = os.CFReleaseThread;
+const global = @import("../../global.zig");
 
 const log = std.log.scoped(.font_shaper);
 
@@ -90,7 +91,7 @@ pub const Shaper = struct {
         unichars: std.ArrayListUnmanaged(u16),
 
         fn init() RunState {
-            return .{ .codepoints = .{}, .unichars = .{} };
+            return .{ .codepoints = .empty, .unichars = .empty };
         }
 
         fn deinit(self: *RunState, alloc: Allocator) void {
@@ -213,18 +214,18 @@ pub const Shaper = struct {
             CFReleaseThread.threadMain,
             .{cf_release_thread},
         );
-        cf_release_thr.setName("cf_release") catch {};
+        cf_release_thr.setName(global.io(), "cf_release") catch {};
 
         return .{
             .alloc = alloc,
-            .cell_buf = .{},
+            .cell_buf = .empty,
             .run_state = run_state,
             .features = features,
             .features_no_default = features_no_default,
             .typesetter_attr_dict = typesetter_attr_dict,
-            .cached_fonts = .{},
+            .cached_fonts = .empty,
             .cached_font_grid = 0,
-            .cf_release_pool = .{},
+            .cf_release_pool = .empty,
             .cf_release_thread = cf_release_thread,
             .cf_release_thr = cf_release_thr,
         };
@@ -282,7 +283,7 @@ pub const Shaper = struct {
         // Send the items. If the send succeeds then we wake up the
         // thread to process the items. If the send fails then do a manual
         // cleanup.
-        if (self.cf_release_thread.mailbox.push(.{ .release = .{
+        if (self.cf_release_thread.mailbox.push(global.io(), .{ .release = .{
             .refs = items,
             .alloc = self.alloc,
         } }, .{ .forever = {} }) != 0) {
@@ -360,7 +361,7 @@ pub const Shaper = struct {
         // Make room for the attributed string, CTTypesetter, and CTLine.
         try self.cf_release_pool.ensureUnusedCapacity(self.alloc, 4);
 
-        const str = macos.foundation.String.createWithCharactersNoCopy(state.unichars.items);
+        const str = try macos.foundation.String.createWithCharactersNoCopy(state.unichars.items);
         self.cf_release_pool.appendAssumeCapacity(str);
 
         // Create an attributed string from our string
@@ -380,7 +381,7 @@ pub const Shaper = struct {
         self.cf_release_pool.appendAssumeCapacity(typesetter);
 
         // Create a line from the typesetter
-        const line = typesetter.createLine(.{ .location = 0, .length = 0 });
+        const line = try typesetter.createLine(.{ .location = 0, .length = 0 });
         self.cf_release_pool.appendAssumeCapacity(line);
 
         // This keeps track of the current x offset (sum of advance.width) and
@@ -606,8 +607,8 @@ pub const Shaper = struct {
             //
             // Because of this, we only acquire the read lock to grab the
             // face and set it up, then release it.
-            grid.lock.lockShared();
-            defer grid.lock.unlockShared();
+            grid.lock.lockSharedUncancelable(global.io());
+            defer grid.lock.unlockShared(global.io());
 
             const face = try grid.resolver.collection.getFace(index);
             const original = face.font;
@@ -842,7 +843,7 @@ test "run iterator" {
     defer testdata.deinit();
 
     {
-        var t: terminal.Terminal = try .init(alloc, .{
+        var t: terminal.Terminal = try .init(testing.io, alloc, .{
             .cols = 5,
             .rows = 3,
         });
@@ -869,7 +870,7 @@ test "run iterator" {
 
     // Spaces should be part of a run
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -892,7 +893,7 @@ test "run iterator" {
 
     {
         // Make a screen with some data
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -917,7 +918,7 @@ test "run iterator" {
     // Bad ligatures
     for (&[_][]const u8{ "fl", "fi", "st" }) |bad| {
         // Make a screen with some data
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -949,7 +950,7 @@ test "run iterator: empty cells with background set" {
 
     {
         // Make a screen with some data
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1009,7 +1010,7 @@ test "shape" {
     buf_idx += try std.unicode.utf8Encode(0x1F3FD, buf[buf_idx..]); // Medium skin tone
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1048,7 +1049,7 @@ test "shape nerd fonts" {
     buf_idx += try std.unicode.utf8Encode(' ', buf[buf_idx..]); // space
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1081,7 +1082,7 @@ test "shape inconsolata ligs" {
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1110,7 +1111,7 @@ test "shape inconsolata ligs" {
     }
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1147,7 +1148,7 @@ test "shape monaspace ligs" {
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1185,7 +1186,7 @@ test "shape left-replaced lig in last run" {
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1223,7 +1224,7 @@ test "shape left-replaced lig in early run" {
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1258,7 +1259,7 @@ test "shape U+3C9 with JB Mono" {
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1295,7 +1296,7 @@ test "shape emoji width" {
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1330,7 +1331,7 @@ test "shape emoji width long" {
     defer testdata.deinit();
 
     // Make a screen and add a long emoji sequence to it.
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     var page = t.screens.active.pages.pages.first.?.page();
@@ -1338,7 +1339,7 @@ test "shape emoji width long" {
     const cell = &row.cells.ptr(page.memory)[0];
     cell.* = .{
         .content_tag = .codepoint,
-        .content = .{ .codepoint = 0x1F9D4 }, // Person with beard
+        .content = .{ .codepoint = .{ .data = 0x1F9D4 } }, // Person with beard
     };
     var graphemes = [_]u21{
         0x1F3FB, // Light skin tone (Fitz 1-2)
@@ -1385,7 +1386,7 @@ test "shape variation selector VS15" {
     buf_idx += try std.unicode.utf8Encode(0xFE0E, buf[buf_idx..]); // ZWJ to force text
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1424,7 +1425,7 @@ test "shape variation selector VS16" {
     buf_idx += try std.unicode.utf8Encode(0xFE0F, buf[buf_idx..]); // ZWJ to force color
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1458,7 +1459,7 @@ test "shape with empty cells in between" {
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1502,7 +1503,7 @@ test "shape Combining characters" {
     buf_idx += try std.unicode.utf8Encode('a', buf[buf_idx..]);
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1552,7 +1553,7 @@ test "shape Devanagari string" {
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Disable grapheme clustering
@@ -1611,7 +1612,7 @@ test "shape Tai Tham vowels (position differs from advance)" {
     buf_idx += try std.unicode.utf8Encode(0x1a70, buf[buf_idx..]); //  ᩰ
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1672,7 +1673,7 @@ test "shape Tai Tham letters (position.y differs from advance)" {
     buf_idx += try std.unicode.utf8Encode(0x1a69, buf[buf_idx..]); // U
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1732,7 +1733,7 @@ test "shape Javanese ligatures" {
     buf_idx += try std.unicode.utf8Encode(0xa9b8, buf[buf_idx..]); // Vowel sign SUKU
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1795,7 +1796,7 @@ test "shape Chakma vowel sign with ligature (vowel sign renders first)" {
     buf_idx += try std.unicode.utf8Encode(0x1112c, buf[buf_idx..]); // Vowel Sign U
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1866,7 +1867,7 @@ test "shape Bengali ligatures with out of order vowels" {
     buf_idx += try std.unicode.utf8Encode(0x09c7, buf[buf_idx..]); // Vowel sign E
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1924,7 +1925,7 @@ test "shape box glyphs" {
     buf_idx += try std.unicode.utf8Encode(0x2501, buf[buf_idx..]); //
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1962,7 +1963,7 @@ test "shape selection boundary" {
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -2067,7 +2068,7 @@ test "shape cursor boundary" {
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -2204,7 +2205,7 @@ test "shape cursor boundary and colored emoji" {
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 3, .rows = 10 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -2301,7 +2302,7 @@ test "shape cell attribute change" {
 
     // Plain >= should shape into 1 run
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -2327,7 +2328,7 @@ test "shape cell attribute change" {
 
     // Bold vs regular should split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -2355,7 +2356,7 @@ test "shape cell attribute change" {
 
     // Changing fg color should split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -2386,7 +2387,7 @@ test "shape cell attribute change" {
 
     // Changing bg color should NOT split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -2417,7 +2418,7 @@ test "shape cell attribute change" {
 
     // Same bg color should not split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -2462,7 +2463,7 @@ test "shape high plane sprite font codepoint" {
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(testing.io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
diff --git a/vendor/libghostty-vt/src/font/shaper/feature.zig b/vendor/libghostty-vt/src/font/shaper/feature.zig
index 5bd73f97..c60eb049 100644
--- a/vendor/libghostty-vt/src/font/shaper/feature.zig
+++ b/vendor/libghostty-vt/src/font/shaper/feature.zig
@@ -1,6 +1,7 @@
 const std = @import("std");
 const assert = @import("../../quirks.zig").inlineAssert;
 const Allocator = std.mem.Allocator;
+const compat_reader = @import("../../lib/compat/reader.zig");
 
 const log = std.log.scoped(.font_shaper);
 
@@ -18,9 +19,8 @@ pub const Feature = struct {
     value: u32,
 
     pub fn fromString(str: []const u8) ?Feature {
-        var fbs = std.io.fixedBufferStream(str);
-        const reader = fbs.reader();
-        return .fromReader(reader);
+        var reader: std.Io.Reader = .fixed(str);
+        return .fromReader(&reader);
     }
 
     /// Parse a single font feature setting from a std.io.Reader, with a version
@@ -55,7 +55,7 @@ pub const Feature = struct {
             done,
         }).start) {
             // If we're done then we skip whitespace until we see a ','.
-            .done => while (true) switch (reader.readByte() catch ',') {
+            .done => while (true) switch (compat_reader.readByte(reader) catch ',') {
                 ' ', '\t' => continue,
                 ',' => break,
                 // If we see something other than whitespace or a ','
@@ -66,11 +66,11 @@ pub const Feature = struct {
             // If we're fast-forwarding from an error we just wanna
             // stop at the first boundary and ignore all other bytes.
             .err => {
-                reader.skipUntilDelimiterOrEof(',') catch {};
+                compat_reader.readSkipUntilDelimiterOrEof(reader, ',') catch {};
                 return null;
             },
 
-            .start => while (true) switch (reader.readByte() catch ',') {
+            .start => while (true) switch (compat_reader.readByte(reader) catch ',') {
                 // Ignore leading whitespace.
                 ' ', '\t' => continue,
                 // Empty feature string.
@@ -97,7 +97,7 @@ pub const Feature = struct {
                 },
             },
 
-            .tag => while (true) switch (reader.readByte() catch ',') {
+            .tag => while (true) switch (compat_reader.readByte(reader) catch ',') {
                 // If the tag is interrupted by a comma it's invalid.
                 ',' => return null,
                 // Ignore quote marks. This does technically ignore cases like
@@ -112,7 +112,7 @@ pub const Feature = struct {
                 },
             },
 
-            .space => while (true) switch (reader.readByte() catch ',') {
+            .space => while (true) switch (compat_reader.readByte(reader) catch ',') {
                 ' ', '\t' => continue,
                 // Ignore quote marks since we might have a
                 // closing quote from the tag still ahead.
@@ -142,7 +142,7 @@ pub const Feature = struct {
                 else => continue :state .err,
             },
 
-            .int => while (true) switch (reader.readByte() catch ',') {
+            .int => while (true) switch (compat_reader.readByte(reader) catch ',') {
                 ',' => break,
                 '0'...'9' => |byte| {
                     // If our value gets too big while
@@ -155,7 +155,7 @@ pub const Feature = struct {
                 else => continue :state .err,
             },
 
-            .bool => while (true) switch (reader.readByte() catch ',') {
+            .bool => while (true) switch (compat_reader.readByte(reader) catch ',') {
                 ',' => return null,
                 'n', 'N' => {
                     // "ofn"
@@ -222,7 +222,7 @@ pub const Feature = struct {
 
 /// A list of font feature settings (see `Feature` for more documentation).
 pub const FeatureList = struct {
-    features: std.ArrayListUnmanaged(Feature) = .{},
+    features: std.ArrayList(Feature) = .empty,
 
     pub fn deinit(self: *FeatureList, alloc: Allocator) void {
         self.features.deinit(alloc);
@@ -243,15 +243,14 @@ pub const FeatureList = struct {
         alloc: Allocator,
         str: []const u8,
     ) !void {
-        var fbs = std.io.fixedBufferStream(str);
-        const reader = fbs.reader();
-        while (fbs.pos < fbs.buffer.len) {
-            const i = fbs.pos;
-            if (Feature.fromReader(reader)) |feature| {
+        var reader: std.Io.Reader = .fixed(str);
+        while (reader.seek < reader.end) {
+            const i = reader.seek;
+            if (Feature.fromReader(&reader)) |feature| {
                 try self.features.append(alloc, feature);
             } else log.warn(
                 "failed to parse font feature setting: \"{s}\"",
-                .{fbs.buffer[i..fbs.pos]},
+                .{reader.buffer[i..reader.seek]},
             );
         }
     }
diff --git a/vendor/libghostty-vt/src/font/shaper/harfbuzz.zig b/vendor/libghostty-vt/src/font/shaper/harfbuzz.zig
index 996aabff..11f9fd23 100644
--- a/vendor/libghostty-vt/src/font/shaper/harfbuzz.zig
+++ b/vendor/libghostty-vt/src/font/shaper/harfbuzz.zig
@@ -15,6 +15,7 @@ const Library = font.Library;
 const SharedGrid = font.SharedGrid;
 const Style = font.Style;
 const Presentation = font.Presentation;
+const global = @import("../../global.zig");
 
 const log = std.log.scoped(.font_shaper);
 
@@ -36,7 +37,7 @@ pub const Shaper = struct {
     /// The codepoints added to the buffer before shaping. We need to keep
     /// these separately because after shaping, HarfBuzz replaces codepoints
     /// with glyph indices in the buffer.
-    codepoints: std.ArrayListUnmanaged(Codepoint) = .{},
+    codepoints: std.ArrayList(Codepoint) = .empty,
 
     const Codepoint = struct {
         cluster: u32,
@@ -87,7 +88,7 @@ pub const Shaper = struct {
         return Shaper{
             .alloc = alloc,
             .hb_buf = try harfbuzz.Buffer.create(),
-            .cell_buf = .{},
+            .cell_buf = .empty,
             .hb_feats = hb_feats,
         };
     }
@@ -134,8 +135,8 @@ pub const Shaper = struct {
             // We have to lock the grid to get the face and unfortunately
             // freetype faces (typically used with harfbuzz) are not thread
             // safe so this has to be an exclusive lock.
-            run.grid.lock.lock();
-            defer run.grid.lock.unlock();
+            run.grid.lock.lockUncancelable(global.io());
+            defer run.grid.lock.unlock(global.io());
 
             const face = try run.grid.resolver.collection.getFace(run.font_index);
             const i = if (!face.quirks_disable_default_font_features) 0 else i: {
@@ -437,13 +438,14 @@ pub const Shaper = struct {
 test "run iterator" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     {
         // Make a screen with some data
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -467,7 +469,7 @@ test "run iterator" {
 
     // Spaces should be part of a run
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -490,7 +492,7 @@ test "run iterator" {
 
     {
         // Make a screen with some data
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -521,13 +523,14 @@ test "run iterator" {
 test "run iterator: empty cells with background set" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     {
         // Make a screen with some data
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -576,6 +579,7 @@ test "run iterator: empty cells with background set" {
 test "shape" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
@@ -587,7 +591,7 @@ test "shape" {
     buf_idx += try std.unicode.utf8Encode(0x1F3FD, buf[buf_idx..]); // Medium skin tone
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -616,12 +620,13 @@ test "shape" {
 test "shape inconsolata ligs" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -650,7 +655,7 @@ test "shape inconsolata ligs" {
     }
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -682,12 +687,13 @@ test "shape inconsolata ligs" {
 test "shape monaspace ligs" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaperWithFont(alloc, .monaspace_neon);
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -723,11 +729,12 @@ test "shape monaspace ligs" {
 test "shape arabic forced LTR" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaperWithFont(alloc, .arabic);
     defer testdata.deinit();
 
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 120, .rows = 30 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 120, .rows = 30 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -763,12 +770,13 @@ test "shape arabic forced LTR" {
 test "shape emoji width" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 5, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -800,12 +808,14 @@ test "shape emoji width" {
 test "shape emoji width long" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     // Make a screen and add a long emoji sequence to it.
     var t = try terminal.Terminal.init(
+        io,
         alloc,
         .{ .cols = 30, .rows = 3 },
     );
@@ -816,7 +826,7 @@ test "shape emoji width long" {
     const cell = &row.cells.ptr(page.memory)[0];
     cell.* = .{
         .content_tag = .codepoint,
-        .content = .{ .codepoint = 0x1F9D4 }, // Person with beard
+        .content = .{ .codepoint = @bitCast(@as(u24, 0x1F9D4)) }, // Person with beard
     };
     var graphemes = [_]u21{
         0x1F3FB, // Light skin tone (Fitz 1-2)
@@ -852,9 +862,45 @@ test "shape emoji width long" {
     try testing.expectEqual(@as(usize, 1), count);
 }
 
+test "shaper selects font for entire grapheme" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+    const io = testing.io;
+
+    var testdata = try testShaper(alloc);
+    defer testdata.deinit();
+
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 5, .rows = 3 });
+    defer t.deinit(alloc);
+
+    var s = t.vtStream();
+    defer s.deinit();
+    s.nextSlice("#\u{20E3}"); // Combining enclosing keycap
+
+    const primary = (try testdata.grid.getIndex(alloc, '#', .regular, null)).?;
+    try testing.expect(testdata.grid.hasCodepoint(primary, '#', null));
+    try testing.expect(!testdata.grid.hasCodepoint(primary, 0x20E3, null));
+
+    const additional = (try testdata.grid.getIndex(alloc, 0x20E3, .regular, null)).?;
+    try testing.expect(testdata.grid.hasCodepoint(additional, '#', null));
+    try testing.expect(testdata.grid.hasCodepoint(additional, 0x20E3, null));
+
+    var state: terminal.RenderState = .empty;
+    defer state.deinit(alloc);
+    try state.update(alloc, &t);
+
+    var it = testdata.shaper.runIterator(.{
+        .grid = testdata.grid,
+        .cells = state.row_data.get(0).cells.slice(),
+    });
+    const run = (try it.next(alloc)).?;
+    try testing.expectEqual(additional, run.font_index);
+}
+
 test "shape variation selector VS15" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
@@ -865,7 +911,7 @@ test "shape variation selector VS15" {
     buf_idx += try std.unicode.utf8Encode(0xFE0E, buf[buf_idx..]); // ZWJ to force text
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -896,6 +942,7 @@ test "shape variation selector VS15" {
 test "shape variation selector VS16" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
@@ -906,7 +953,7 @@ test "shape variation selector VS16" {
     buf_idx += try std.unicode.utf8Encode(0xFE0F, buf[buf_idx..]); // ZWJ to force color
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -937,12 +984,14 @@ test "shape variation selector VS16" {
 test "shape with empty cells in between" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     // Make a screen with some data
     var t = try terminal.Terminal.init(
+        io,
         alloc,
         .{ .cols = 30, .rows = 3 },
     );
@@ -977,6 +1026,7 @@ test "shape with empty cells in between" {
 test "shape Combining characters" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
@@ -990,6 +1040,7 @@ test "shape Combining characters" {
 
     // Make a screen with some data
     var t = try terminal.Terminal.init(
+        io,
         alloc,
         .{ .cols = 30, .rows = 3 },
     );
@@ -1029,6 +1080,7 @@ test "shape Combining characters" {
 test "shape Devanagari string" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     // We need a font that supports devanagari for this to work, if we can't
     // find Arial Unicode MS, which is a system font on macOS, we just skip
@@ -1040,7 +1092,7 @@ test "shape Devanagari string" {
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Disable grapheme clustering
@@ -1087,6 +1139,7 @@ test "shape Tai Tham vowels (position differs from advance)" {
     // // behavior.
     // const testing = std.testing;
     // const alloc = testing.allocator;
+    // const io = testing.io;
 
     // // We need a font that supports Tai Tham for this to work, if we can't find
     // // Noto Sans Tai Tham, which is a system font on macOS, we just skip the
@@ -1103,7 +1156,7 @@ test "shape Tai Tham vowels (position differs from advance)" {
     // buf_idx += try std.unicode.utf8Encode(0x1a70, buf[buf_idx..]); //  ᩰ
 
     // // Make a screen with some data
-    // var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    // var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     // defer t.deinit(alloc);
 
     // // Enable grapheme clustering
@@ -1147,6 +1200,7 @@ test "shape Tai Tham vowels (position differs from advance)" {
 test "shape Tibetan characters" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     // We need a font that has multiple glyphs for this codepoint to reproduce
     // the old broken behavior, and Noto Serif Tibetan is one of them. It's not
@@ -1162,7 +1216,7 @@ test "shape Tibetan characters" {
     buf_idx += try std.unicode.utf8Encode(0x0f00, buf[buf_idx..]); // ༀ
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1203,6 +1257,7 @@ test "shape Tai Tham letters (run_offset.y differs from zero)" {
     return error.SkipZigTest;
     // const testing = std.testing;
     // const alloc = testing.allocator;
+    // const io = testing.io;
 
     // // We need a font that supports Tai Tham for this to work, if we can't find
     // // Noto Sans Tai Tham, which is a system font on macOS, we just skip the
@@ -1224,7 +1279,7 @@ test "shape Tai Tham letters (run_offset.y differs from zero)" {
     // buf_idx += try std.unicode.utf8Encode(0x1a69, buf[buf_idx..]); // U
 
     // // Make a screen with some data
-    // var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    // var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     // defer t.deinit(alloc);
 
     // // Enable grapheme clustering
@@ -1266,6 +1321,7 @@ test "shape Javanese ligatures" {
     return error.SkipZigTest;
     // const testing = std.testing;
     // const alloc = testing.allocator;
+    // const io = testing.io;
 
     // // We need a font that supports Javanese for this to work, if we can't find
     // // Noto Sans Javanese Regular, which is a system font on macOS, we just
@@ -1287,7 +1343,7 @@ test "shape Javanese ligatures" {
     // buf_idx += try std.unicode.utf8Encode(0xa9b8, buf[buf_idx..]); // Vowel sign SUKU
 
     // // Make a screen with some data
-    // var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    // var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     // defer t.deinit(alloc);
 
     // // Enable grapheme clustering
@@ -1327,6 +1383,7 @@ test "shape Javanese ligatures" {
 test "shape Chakma vowel sign with ligature (vowel sign renders first)" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     // We need a font that supports Chakma for this to work, if we can't find
     // Noto Sans Chakma Regular, which is a system font on macOS, we just skip
@@ -1350,7 +1407,7 @@ test "shape Chakma vowel sign with ligature (vowel sign renders first)" {
     buf_idx += try std.unicode.utf8Encode(0x1112c, buf[buf_idx..]); // Vowel Sign U
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1398,6 +1455,7 @@ test "shape Bengali ligatures with out of order vowels" {
 
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     // We need a font that supports Bengali for this to work, if we can't find
     // Arial Unicode MS, which is a system font on macOS, we just skip the
@@ -1425,7 +1483,7 @@ test "shape Bengali ligatures with out of order vowels" {
     buf_idx += try std.unicode.utf8Encode(0x09c7, buf[buf_idx..]); // Vowel sign E
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 30, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 30, .rows = 3 });
     defer t.deinit(alloc);
 
     // Enable grapheme clustering
@@ -1472,6 +1530,7 @@ test "shape Bengali ligatures with out of order vowels" {
 test "shape box glyphs" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
@@ -1482,7 +1541,7 @@ test "shape box glyphs" {
     buf_idx += try std.unicode.utf8Encode(0x2501, buf[buf_idx..]); //
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1516,12 +1575,13 @@ test "shape box glyphs" {
 test "shape selection boundary" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1621,12 +1681,13 @@ test "shape selection boundary" {
 test "shape cursor boundary" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     // Make a screen with some data
-    var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+    var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
     defer t.deinit(alloc);
 
     var s = t.vtStream();
@@ -1758,12 +1819,14 @@ test "shape cursor boundary" {
 test "shape cursor boundary and colored emoji" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     // Make a screen with some data
     var t = try terminal.Terminal.init(
+        io,
         alloc,
         .{ .cols = 3, .rows = 10 },
     );
@@ -1857,13 +1920,14 @@ test "shape cursor boundary and colored emoji" {
 test "shape cell attribute change" {
     const testing = std.testing;
     const alloc = testing.allocator;
+    const io = testing.io;
 
     var testdata = try testShaper(alloc);
     defer testdata.deinit();
 
     // Plain >= should shape into 1 run
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 10, .rows = 3 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 10, .rows = 3 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1889,7 +1953,7 @@ test "shape cell attribute change" {
 
     // Bold vs regular should split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1917,7 +1981,7 @@ test "shape cell attribute change" {
 
     // Changing fg color should split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1948,7 +2012,7 @@ test "shape cell attribute change" {
 
     // Changing bg color should not split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
@@ -1979,7 +2043,7 @@ test "shape cell attribute change" {
 
     // Same bg color should not split
     {
-        var t = try terminal.Terminal.init(alloc, .{ .cols = 3, .rows = 10 });
+        var t = try terminal.Terminal.init(io, alloc, .{ .cols = 3, .rows = 10 });
         defer t.deinit(alloc);
 
         var s = t.vtStream();
diff --git a/vendor/libghostty-vt/src/font/shaper/run.zig b/vendor/libghostty-vt/src/font/shaper/run.zig
index 45c5d38c..9f33ba32 100644
--- a/vendor/libghostty-vt/src/font/shaper/run.zig
+++ b/vendor/libghostty-vt/src/font/shaper/run.zig
@@ -348,47 +348,34 @@ pub const RunIterator = struct {
         // we just return whatever index for the cell codepoint.
         if (!cell.hasGrapheme()) return primary;
 
-        // If this is a grapheme, we need to find a font that supports
-        // all of the codepoints in the grapheme.
-        var candidates: std.ArrayList(font.Collection.Index) = try .initCapacity(
-            alloc,
-            graphemes.len + 1,
-        );
-        defer candidates.deinit(alloc);
-        candidates.appendAssumeCapacity(primary);
+        // Try the primary font followed by the font selected for each
+        // additional codepoint until one supports the entire grapheme.
+        candidate: for (0..graphemes.len + 1) |i| {
+            const idx = if (i == 0) primary else idx: {
+                const cp = graphemes[i - 1];
 
-        for (graphemes) |cp| {
-            // Ignore Emoji ZWJs
-            if (cp == 0xFE0E or cp == 0xFE0F or cp == 0x200D) continue;
+                // Ignore Emoji ZWJs
+                if (cp == 0xFE0E or cp == 0xFE0F or cp == 0x200D) continue :candidate;
 
-            // Find a font that supports this codepoint. If none support this
-            // then the whole grapheme can't be rendered so we return null.
-            //
-            // We explicitly do not require the additional grapheme components
-            // to support the base presentation, since it is common for emoji
-            // fonts to support the base emoji with emoji presentation but not
-            // certain ZWJ-combined characters like the male and female signs.
-            const idx = try self.opts.grid.getIndex(
-                alloc,
-                cp,
-                style,
-                null,
-            ) orelse return null;
-            candidates.appendAssumeCapacity(idx);
-        }
+                // We explicitly do not require the additional grapheme components
+                // to support the base presentation, since it is common for emoji
+                // fonts to support the base emoji with emoji presentation but not
+                // certain ZWJ-combined characters like the male and female signs.
+                break :idx try self.opts.grid.getIndex(
+                    alloc,
+                    cp,
+                    style,
+                    null,
+                ) orelse return null;
+            };
 
-        // We need to find a candidate that has ALL of our codepoints
-        for (candidates.items) |idx| {
             if (!self.opts.grid.hasCodepoint(idx, primary_cp, presentation)) continue;
             for (graphemes) |cp| {
                 // Ignore Emoji ZWJs
                 if (cp == 0xFE0E or cp == 0xFE0F or cp == 0x200D) continue;
-                if (!self.opts.grid.hasCodepoint(idx, cp, null)) break;
-            } else {
-                // If the while completed, then we have a candidate that
-                // supports all of our codepoints.
-                return idx;
+                if (!self.opts.grid.hasCodepoint(idx, cp, null)) continue :candidate;
             }
+            return idx;
         }
 
         return null;
diff --git a/vendor/libghostty-vt/src/font/sprite/Face.zig b/vendor/libghostty-vt/src/font/sprite/Face.zig
index fd029d13..e2e37d2a 100644
--- a/vendor/libghostty-vt/src/font/sprite/Face.zig
+++ b/vendor/libghostty-vt/src/font/sprite/Face.zig
@@ -273,15 +273,16 @@ fn testDiffAtlas(
     // Get the file contents, we compare the PNG data first in
     // order to ensure that no one smuggles arbitrary binary
     // data in to the reference PNGs.
-    const test_file = try std.fs.openFileAbsolute(path, .{ .mode = .read_only });
-    defer test_file.close();
-    const test_bytes = try test_file.readToEndAlloc(
+    const test_file = try std.Io.Dir.openFileAbsolute(std.testing.io, path, .{ .mode = .read_only });
+    defer test_file.close(std.testing.io);
+    var test_file_reader = test_file.reader(std.testing.io, &.{});
+    const test_bytes = try test_file_reader.interface.readAlloc(
         alloc,
-        std.math.maxInt(usize),
+        (try test_file.stat(std.testing.io)).size,
     );
     defer alloc.free(test_bytes);
 
-    const cwd_absolute = try std.fs.cwd().realpathAlloc(alloc, ".");
+    const cwd_absolute = try std.Io.Dir.cwd().realPathFileAlloc(std.testing.io, ".", alloc);
     defer alloc.free(cwd_absolute);
 
     // Get the reference file contents to compare.
@@ -292,7 +293,7 @@ fn testDiffAtlas(
     );
     defer alloc.free(ref_path);
     const ref_file =
-        std.fs.cwd().openFile(ref_path, .{ .mode = .read_only }) catch |err| {
+        std.Io.Dir.cwd().openFile(std.testing.io, ref_path, .{ .mode = .read_only }) catch |err| {
             log.err("Can't open reference file {s}: {}\n", .{
                 ref_path,
                 err,
@@ -306,14 +307,15 @@ fn testDiffAtlas(
                 .{ cwd_absolute, i, i + 0xFF, width, height, thickness },
             );
             defer alloc.free(test_path);
-            try std.fs.copyFileAbsolute(path, test_path, .{});
+            try std.Io.Dir.copyFileAbsolute(path, test_path, std.testing.io, .{});
 
             return true;
         };
-    defer ref_file.close();
-    const ref_bytes = try ref_file.readToEndAlloc(
+    defer ref_file.close(std.testing.io);
+    var ref_file_reader = ref_file.reader(std.testing.io, &.{});
+    const ref_bytes = try ref_file_reader.interface.readAlloc(
         alloc,
-        std.math.maxInt(usize),
+        (try ref_file.stat(std.testing.io)).size,
     );
     defer alloc.free(ref_bytes);
 
@@ -330,7 +332,7 @@ fn testDiffAtlas(
         .{ cwd_absolute, i, i + 0xFF, width, height, thickness },
     );
     defer alloc.free(test_path);
-    try std.fs.copyFileAbsolute(path, test_path, .{});
+    try std.Io.Dir.copyFileAbsolute(path, test_path, std.testing.io, .{});
 
     // Use wuffs to decode the reference PNG to raw pixels.
     // These will be RGBA, so when diffing we can just compare
@@ -394,7 +396,7 @@ fn testDiffAtlas(
         .{ i, i + 0xFF, width, height, thickness },
     );
     defer alloc.free(diff_path);
-    try z2d.png_exporter.writeToPNGFile(diff, diff_path, .{});
+    try z2d.png_exporter.writeToPNGFile(std.testing.io, diff, diff_path, .{});
     log.err(
         "One or more glyphs differ from reference file in range U+{X}...U+{X}! " ++
             "test={s}, reference={s}, diff={s}",
@@ -462,7 +464,7 @@ fn testDrawRanges(
     // Try to make the sprite_face_test folder if it doesn't already exist.
     var dir = testing.tmpDir(.{});
     defer dir.cleanup();
-    const tmp_dir = try dir.dir.realpathAlloc(alloc, ".");
+    const tmp_dir = try dir.dir.realPathFileAlloc(testing.io, ".", alloc);
     defer alloc.free(tmp_dir);
 
     // We set this to true if we have any fails so we can
@@ -481,7 +483,7 @@ fn testDrawRanges(
                     .{ tmp_dir, i, i + 0xFF, width, height, thickness },
                 );
                 defer alloc.free(path);
-                try z2d.png_exporter.writeToPNGFile(atlas, path, .{});
+                try z2d.png_exporter.writeToPNGFile(testing.io, atlas, path, .{});
 
                 if (try testDiffAtlas(
                     alloc,
@@ -526,7 +528,7 @@ fn testDrawRanges(
         .{ tmp_dir, i, i + 0xFF, width, height, thickness },
     );
     defer alloc.free(path);
-    try z2d.png_exporter.writeToPNGFile(atlas, path, .{});
+    try z2d.png_exporter.writeToPNGFile(std.testing.io, atlas, path, .{});
     if (try testDiffAtlas(
         alloc,
         &atlas,
diff --git a/vendor/libghostty-vt/src/font/sprite/canvas.zig b/vendor/libghostty-vt/src/font/sprite/canvas.zig
index 7904f20a..da54ac27 100644
--- a/vendor/libghostty-vt/src/font/sprite/canvas.zig
+++ b/vendor/libghostty-vt/src/font/sprite/canvas.zig
@@ -5,6 +5,7 @@ const assert = @import("../../quirks.zig").inlineAssert;
 const Allocator = std.mem.Allocator;
 const z2d = @import("z2d");
 const font = @import("../main.zig");
+const global = @import("../../global.zig");
 
 pub fn Point(comptime T: type) type {
     return struct {
@@ -255,7 +256,7 @@ pub const Canvas = struct {
 
     /// Acquires a z2d drawing context, caller MUST deinit context.
     pub fn getContext(self: *Canvas) z2d.Context {
-        var ctx = z2d.Context.init(self.alloc, &self.sfc);
+        var ctx = z2d.Context.init(global.io(), self.alloc, &self.sfc);
         // Offset by our padding to keep
         // coordinates relative to the cell.
         ctx.setTransformation(self.transformation());
@@ -374,85 +375,17 @@ pub const Canvas = struct {
         );
     }
 
-    /// Do an inner stroke on a z2d path, right now this involves a pretty
-    /// heavy workaround that uses two extra surfaces; in the future, z2d
-    /// should add inner and outer strokes natively.
+    /// Do an inner stroke using a 1/2 stroke width inset of the supplied
+    /// `path`.
     pub fn innerStrokePath(
         self: *Canvas,
         path: z2d.Path,
         opts: z2d.painter.StrokeOptions,
         color: Color,
-    ) (z2d.painter.StrokeError || z2d.painter.FillError)!void {
-        // On one surface we fill the shape, this will be a mask we
-        // multiply with the double-width stroke so that only the
-        // part inside is used.
-        var fill_sfc: z2d.Surface = try .init(
-            .image_surface_alpha8,
-            self.alloc,
-            self.sfc.getWidth(),
-            self.sfc.getHeight(),
-        );
-        defer fill_sfc.deinit(self.alloc);
-
-        // On the other we'll do the double width stroke.
-        var stroke_sfc: z2d.Surface = try .init(
-            .image_surface_alpha8,
-            self.alloc,
-            self.sfc.getWidth(),
-            self.sfc.getHeight(),
-        );
-        defer stroke_sfc.deinit(self.alloc);
-
-        // Make a closed version of the path for our fill, so
-        // that we can support open paths for inner stroke.
-        var closed_path = path;
-        closed_path.nodes = try path.nodes.clone(self.alloc);
-        defer closed_path.deinit(self.alloc);
-        try closed_path.close(self.alloc);
-
-        // Fill the shape in white to the fill surface, we use
-        // white because this is a mask that we'll multiply with
-        // the stroke, we want everything inside to be the stroke
-        // color.
-        try z2d.painter.fill(
-            self.alloc,
-            &fill_sfc,
-            &.{ .opaque_pattern = .{
-                .pixel = .{ .alpha8 = .{ .a = 255 } },
-            } },
-            closed_path.nodes.items,
-            .{},
-        );
-
-        // Stroke the shape with double the desired width.
-        var mut_opts = opts;
-        mut_opts.line_width *= 2;
-        try z2d.painter.stroke(
-            self.alloc,
-            &stroke_sfc,
-            &.{ .opaque_pattern = .{
-                .pixel = .{ .alpha8 = .{ .a = @intFromEnum(color) } },
-            } },
-            path.nodes.items,
-            mut_opts,
-        );
-
-        // We multiply the stroke sfc on to the fill surface.
-        // The z2d composite operation doesn't seem to work for
-        // this with alpha8 surfaces, so we have to do it manually.
-        for (
-            std.mem.sliceAsBytes(fill_sfc.image_surface_alpha8.buf),
-            std.mem.sliceAsBytes(stroke_sfc.image_surface_alpha8.buf),
-        ) |*d, s| {
-            d.* = @intFromFloat(@round(
-                255.0 *
-                    (@as(f64, @floatFromInt(s)) / 255.0) *
-                    (@as(f64, @floatFromInt(d.*)) / 255.0),
-            ));
-        }
-
-        // Then we composite the result on to the main surface.
-        self.sfc.composite(&fill_sfc, .src_over, 0, 0, .{});
+    ) (z2d.Path.OffsetError || z2d.painter.StrokeError)!void {
+        var inset_path = try path.offset(self.alloc, -opts.line_width / 2.0);
+        defer inset_path.deinit(self.alloc);
+        return self.strokePath(inset_path, opts, color);
     }
 
     /// Fill a z2d path.
diff --git a/vendor/libghostty-vt/src/font/sprite/draw/powerline.zig b/vendor/libghostty-vt/src/font/sprite/draw/powerline.zig
index 8658d855..35445cdd 100644
--- a/vendor/libghostty-vt/src/font/sprite/draw/powerline.zig
+++ b/vendor/libghostty-vt/src/font/sprite/draw/powerline.zig
@@ -292,8 +292,13 @@ pub fn drawE0B5(
 
     const radius: f64 = @min(float_width, float_height / 2);
 
-    var path = canvas.staticPath(4);
+    // Note on the first/final lineTo moves: this is to enforce horizontal
+    // lines on both ends. This ensures that when the path is offset and
+    // stroked, the ends are butt-capped entirely perpendicularly; curveTo
+    // lerping would produce very slight slopes otherwise.
+    var path = canvas.staticPath(6);
     path.moveTo(0, 0);
+    path.lineTo(1, 0);
     path.curveTo(
         radius * c,
         0,
@@ -308,9 +313,10 @@ pub fn drawE0B5(
         float_height - radius + radius * c,
         radius * c,
         float_height,
-        0,
+        1,
         float_height,
     );
+    path.lineTo(0, float_height);
 
     try canvas.innerStrokePath(path.wrapped_path, .{
         .line_width = @floatFromInt(metrics.box_thickness),
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-11x21+2.png
index e04e7726..00ee592b 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-12x24+3.png
index ce1b1c42..7b37e566 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-18x36+4.png
index 1c21f688..6b19f819 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-9x17+1.png
index 459822e6..04c9ac6a 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CC00...U+1CCFF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-11x21+2.png
index 8d7de36a..898264f3 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-12x24+3.png
index ab6bec96..59da98ba 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-18x36+4.png
index 43035aef..e3dff1f3 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-9x17+1.png
index fc111e2d..6069996b 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CD00...U+1CDFF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-11x21+2.png
index b3cda82d..3cbf0934 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-12x24+3.png
index e076da7c..9f62fc4b 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-18x36+4.png
index 366be386..ded30f0f 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-9x17+1.png
index 5cd7a4ef..260e536d 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1CE00...U+1CEFF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-11x21+2.png
index 023396fe..6f408b37 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-12x24+3.png
index 1a4dcb01..99da9148 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-18x36+4.png
index 73ead485..e2136d7d 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-9x17+1.png
index b58ded46..2db1f743 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+1FB00...U+1FBFF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-11x21+2.png
index 9ae5b45f..eb0032eb 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-12x24+3.png
index 89011df4..99032356 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-18x36+4.png
index 05ff2a5f..9d6fc664 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-9x17+1.png
index cf96b7d1..5c6ef4db 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2500...U+25FF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-11x21+2.png
index 804e3017..f171dd24 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-12x24+3.png
index aa3e2f99..4ccdfc4a 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-18x36+4.png
index 49f431a4..47e70eee 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-9x17+1.png
index 4308c536..5f0928e2 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+2800...U+28FF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-11x21+2.png
index addd1f49..905adfdc 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-12x24+3.png
index 70ae8102..c19a7bc0 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-18x36+4.png
index 32a42097..052ee7e7 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-9x17+1.png
index 46151697..159c7721 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+E000...U+E0FF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-11x21+2.png
index 10385379..94deceb4 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-12x24+3.png
index b1bb803a..59323c67 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-18x36+4.png
index e7415b7a..05a124ec 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-9x17+1.png
index 730a4c42..dcb16b3d 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F500...U+F5FF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-11x21+2.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-11x21+2.png
index b216174e..de2772e7 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-11x21+2.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-11x21+2.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-12x24+3.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-12x24+3.png
index 2243248b..8cf94a51 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-12x24+3.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-12x24+3.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-18x36+4.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-18x36+4.png
index f3a887d2..9e93a93a 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-18x36+4.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-18x36+4.png
diff --git a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-9x17+1.png b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-9x17+1.png
index 82ce8246..7bfd9db2 100644
--- a/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-9x17+1.png
+++ b/vendor/libghostty-vt/src/font/sprite/testdata/U+F600...U+F6FF-9x17+1.png
diff --git a/vendor/libghostty-vt/src/font/testdata/glyf_rasterize.png b/vendor/libghostty-vt/src/font/testdata/glyf_rasterize.png
index f5f8fb81..689e3e91 100644
--- a/vendor/libghostty-vt/src/font/testdata/glyf_rasterize.png
+++ b/vendor/libghostty-vt/src/font/testdata/glyf_rasterize.png