fix: keep cjk ime agent allow-list safe

refs #149

6 files changed, 40 insertions, 4 deletions

diff --git a/src/app/mod.rs b/src/app/mod.rs
index 5cc40ecc..4c4845a1 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -428,6 +428,7 @@ impl App {
             prompt_new_tab_name: config.ui.prompt_new_tab_name,
             show_agent_labels_on_pane_borders: config.ui.show_agent_labels_on_pane_borders,
             reveal_hidden_cursor_for_cjk_ime: config.experimental.reveal_hidden_cursor_for_cjk_ime,
+            cjk_ime_agent_filter_configured: !config.experimental.cjk_ime_agents.is_empty(),
             cjk_ime_agents: parse_cjk_ime_agents(&config.experimental.cjk_ime_agents),
             cjk_ime_cursor_shape: config.experimental.cjk_ime_cursor_shape.to_decscusr(),
             kitty_graphics_enabled: config.experimental.kitty_graphics,
@@ -907,6 +908,8 @@ impl App {
             }
             self.state.reveal_hidden_cursor_for_cjk_ime =
                 config.experimental.reveal_hidden_cursor_for_cjk_ime;
+            self.state.cjk_ime_agent_filter_configured =
+                !config.experimental.cjk_ime_agents.is_empty();
             self.state.cjk_ime_agents = parse_cjk_ime_agents(&config.experimental.cjk_ime_agents);
             self.state.cjk_ime_cursor_shape =
                 config.experimental.cjk_ime_cursor_shape.to_decscusr();
diff --git a/src/app/state.rs b/src/app/state.rs
index 1566fdeb..6924dc65 100644
--- a/src/app/state.rs
+++ b/src/app/state.rs
@@ -969,7 +969,8 @@ pub struct AppState {
     /// the pane requested `?25l`. See `[experimental] reveal_hidden_cursor_for_cjk_ime`.
     pub reveal_hidden_cursor_for_cjk_ime: bool,
     /// Restrict cursor reveal to focused panes whose detected agent matches
-    /// one of these. Empty means apply to any focused pane.
+    /// one of these. When false, apply to any focused pane.
+    pub cjk_ime_agent_filter_configured: bool,
     pub cjk_ime_agents: Vec<crate::detect::Agent>,
     /// DECSCUSR shape parameter (1–6) for the IME anchor cursor.
     pub cjk_ime_cursor_shape: u8,
@@ -1233,6 +1234,7 @@ impl AppState {
             prompt_new_tab_name: true,
             show_agent_labels_on_pane_borders: false,
             reveal_hidden_cursor_for_cjk_ime: false,
+            cjk_ime_agent_filter_configured: false,
             cjk_ime_agents: Vec::new(),
             cjk_ime_cursor_shape: 2, // steady_block
             kitty_graphics_enabled: false,
diff --git a/src/config/model.rs b/src/config/model.rs
index ba52d579..40d425a3 100644
--- a/src/config/model.rs
+++ b/src/config/model.rs
@@ -265,7 +265,8 @@ pub struct ExperimentalConfig {
     pub reveal_hidden_cursor_for_cjk_ime: bool,
     /// Restrict `reveal_hidden_cursor_for_cjk_ime` to focused panes whose
     /// detected agent matches one of these names (case-insensitive). Empty
-    /// list means apply to any focused pane. Unknown agent names are ignored.
+    /// list means apply to any focused pane. Unknown agent names are ignored;
+    /// if the list contains no valid names, the reveal does not apply.
     /// Accepted names: pi, claude, codex, gemini, cursor, cline, opencode,
     /// copilot, kimi, kiro, droid, amp, grok, hermes. Default: empty.
     pub cjk_ime_agents: Vec<String>,
diff --git a/src/main.rs b/src/main.rs
index 440a87a5..17052159 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -209,6 +209,7 @@ const DEFAULT_CONFIG: &str = r##"# herdr configuration
 # reveal_hidden_cursor_for_cjk_ime = false
 # Optional allow-list: only reveal for focused panes whose detected agent
 # matches one of these names. Empty means apply to any focused pane.
+# If the list contains no valid names, the reveal does not apply.
 # Accepted: pi, claude, codex, gemini, cursor, cline, opencode, copilot,
 # kimi, kiro, droid, amp, grok, hermes.
 # cjk_ime_agents = []
diff --git a/src/server/headless.rs b/src/server/headless.rs
index f56dbdeb..539892e0 100644
--- a/src/server/headless.rs
+++ b/src/server/headless.rs
@@ -2804,6 +2804,7 @@ mod tests {
         state.reveal_hidden_cursor_for_cjk_ime = true;
         // Filter only Claude, but the test pane has no detected agent, so the
         // reveal must not apply.
+        state.cjk_ime_agent_filter_configured = true;
         state.cjk_ime_agents = vec![crate::detect::Agent::Claude];
         let mut ws = crate::workspace::Workspace::test_new("test");
         let pane_id = ws.tabs[0].root_pane;
@@ -2828,6 +2829,34 @@ mod tests {
     }
 
     #[tokio::test]
+    async fn virtual_render_skips_reveal_when_agent_filter_has_no_valid_entries() {
+        let mut state = AppState::test_new();
+        state.reveal_hidden_cursor_for_cjk_ime = true;
+        state.cjk_ime_agent_filter_configured = true;
+        state.cjk_ime_agents = Vec::new();
+        let mut ws = crate::workspace::Workspace::test_new("test");
+        let pane_id = ws.tabs[0].root_pane;
+        ws.insert_test_runtime(
+            pane_id,
+            crate::terminal::TerminalRuntime::test_with_screen_bytes(20, 5, b"left\x1b[?25l"),
+        );
+
+        state.workspaces = vec![ws];
+        state.active = Some(0);
+        state.selected = 0;
+        state.mode = crate::app::Mode::Terminal;
+
+        let area = Rect::new(0, 0, 80, 24);
+        let (_buffer, cursor) =
+            crate::server::render_stream::render_virtual(&mut state, area, true);
+
+        assert!(
+            cursor.as_ref().is_none_or(|cursor| !cursor.visible),
+            "agent filter with no valid entries should suppress reveal; got {cursor:?}",
+        );
+    }
+
+    #[tokio::test]
     async fn virtual_render_omits_focused_pane_cursor_while_mobile_switcher_open() {
         let mut state = AppState::test_new();
         let mut ws = crate::workspace::Workspace::test_new("test");
diff --git a/src/server/render_stream.rs b/src/server/render_stream.rs
index 6dd4ad48..b6e50444 100644
--- a/src/server/render_stream.rs
+++ b/src/server/render_stream.rs
@@ -327,9 +327,9 @@ fn focused_terminal_cursor(app_state: &AppState) -> Option<CursorState> {
     // Determine whether the IME-anchor reveal applies to this focused pane.
     // The master switch must be on, and either no agent filter is configured
     // (apply to any pane) or the focused pane's detected agent matches the
-    // allow-list.
+    // allow-list. A configured list with no valid entries reveals nothing.
     let reveal = app_state.reveal_hidden_cursor_for_cjk_ime
-        && (app_state.cjk_ime_agents.is_empty() || {
+        && (!app_state.cjk_ime_agent_filter_configured || {
             let detected = app_state
                 .workspaces
                 .get(ws_idx)