fix: backport libghostty resize overflow fix

refs #465

1 files changed, 40 insertions, 0 deletions

diff --git a/vendor/libghostty-vt.patches.md b/vendor/libghostty-vt.patches.md
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+# libghostty-vt local patches
+
+This file tracks intentional local changes applied on top of the vendored
+`libghostty-vt` source. Remove a patch only when the vendored source commit
+contains the upstream fix and the listed verification still passes.
+
+## 0001 backport resizeCols cursor subtraction saturation
+
+status: active
+
+patch: `vendor/patches/libghostty-vt/0001-backport-resizecols-cursor-subtraction.patch`
+
+herdr issue: https://github.com/ogulcancelik/herdr/issues/465
+
+upstream discussion: https://github.com/ghostty-org/ghostty/discussions/12905
+
+upstream pr: https://github.com/ghostty-org/ghostty/pull/12907
+
+introduced upstream: `c44afa625`
+
+vendored base: `0f7cd84b880b203c98683e520e84b9db0c5938d8`
+
+local files:
+
+- `vendor/libghostty-vt/src/terminal/PageList.zig`
+- `vendor/libghostty-vt/src/terminal/c/terminal.zig`
+
+reason: shrinking rows and columns in one resize can leave the pre-resize
+cursor row past the new row count. `PageList.resizeCols` then computed rows
+below the cursor with checked unsigned subtraction and aborted in safety builds.
+
+remove when: the vendored source commit contains upstream PR #12907 and the
+local ReleaseSafe resize regression tests pass without this patch.
+
+verification:
+
+```sh
+zig build test-lib-vt -Demit-lib-vt -Doptimize=ReleaseSafe -Dtest-filter="resize shrinks both axes with cursor at bottom"
+zig build test-lib-vt -Demit-lib-vt -Doptimize=ReleaseSafe -Dtest-filter="PageList resize less rows and cols cursor at bottom"
+```