feat(input): smart Ctrl+C — copy selection or send SIGINT

CHANGELOG.md

@@ -12,6 +12,7 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ### Changed
 - input mode (normal/insert/visual/search) is now tracked per tab; switching tabs restores each tab's own mode
+- Ctrl+C now copies only when there is an active selection, otherwise it sends SIGINT
 
 
 ## [0.9.0] - 2026-07-05

README.md

@@ -326,7 +326,7 @@ Navigate freely to position the cursor, press `v` to set the selection anchor, t
 | `g` / `G` | Top / bottom of viewport |
 | `v` | Set selection anchor at cursor (starts highlighting) |
 | `o` | Swap anchor and cursor |
-| `y` / `Ctrl+C` | Copy selection and exit |
+| `y` / `Ctrl+C` | Copy selection and exit (`Ctrl+C` copies only with an active selection; otherwise it sends SIGINT) |
 | `Y` | Yank (copy) the entire line at cursor |
 | `q` / `Escape` | Exit to Insert mode |
 

doc/SPEC.md

@@ -563,7 +563,7 @@ actions shift the anchor coordinates so the selected content stays stable.
 | `g` / `G` | Top / bottom of viewport |
 | `v` | Set selection anchor at cursor (activates highlight) |
 | `o` | Swap anchor and cursor (extend from either end) |
-| `y` / `Ctrl+C` | Copy selection to clipboard, return to Insert mode |
+| `y` / `Ctrl+C` | Copy selection to clipboard, return to Insert mode (`Ctrl+C` copies only with an active selection; otherwise it sends SIGINT) |
 | `Y` | Yank (copy) the entire line at the cursor, return to Insert mode |
 | `q` / `Escape` | Exit to Insert mode |
 

src/input/keybindings.rs

@@ -246,6 +246,16 @@ fn shift_scroll_action(key: &Key, grid_rows: usize) -> Option<Action> {
     }
 }
 
+/// Ctrl+C copies only when there is a real (anchored) selection; in every
+/// other mode (Insert, Normal, un-anchored Visual) it sends SIGINT (0x03).
+fn ctrl_c_action(mode: &InputMode) -> Action {
+    if matches!(mode, InputMode::Visual { anchored: true, .. }) {
+        Action::Copy
+    } else {
+        Action::SendToPty(vec![3])
+    }
+}
+
 fn handle_ctrl_only(key: &Key, alt: bool, mode: &InputMode) -> Option<Action> {
     if let Key::Character(s) = key {
         if s.eq_ignore_ascii_case("w") {
@@ -254,8 +264,8 @@ fn handle_ctrl_only(key: &Key, alt: bool, mode: &InputMode) -> Option<Action> {
         if let Some(a) = ctrl_special_char_action(s, mode) {
             return Some(a);
         }
-        if s.eq_ignore_ascii_case("c") && matches!(mode, InputMode::Visual { .. }) {
-            return Some(Action::Copy);
+        if s.eq_ignore_ascii_case("c") {
+            return Some(ctrl_c_action(mode));
         }
     }
     ctrl_char_action(key, alt)

src/input/keybindings_test.rs

@@ -328,19 +328,64 @@ fn ctrl_shift_end_scrolls_to_bottom() {
     assert!(matches!(a, Action::ScrollToBottom));
 }
 
+fn visual_anchored() -> InputMode {
+    InputMode::Visual {
+        start_col: 0,
+        start_row: 0,
+        cur_col: 0,
+        cur_row: 0,
+        anchored: true,
+    }
+}
+
 #[test]
-fn ctrl_c_in_visual_copies() {
-    let a = handle_key_inner(&char_key("c"), true, false, false, &visual(), 80, 24, false);
+fn ctrl_c_in_anchored_visual_copies() {
+    let a = handle_key_inner(
+        &char_key("c"),
+        true,
+        false,
+        false,
+        &visual_anchored(),
+        80,
+        24,
+        false,
+    );
     assert!(matches!(a, Action::Copy));
 }
 
+#[test]
+fn ctrl_c_in_unanchored_visual_sends_sigint() {
+    // Un-anchored Visual has no highlighted selection; ctrl+c must send SIGINT,
+    // not a no-op Copy.
+    let a = handle_key_inner(&char_key("c"), true, false, false, &visual(), 80, 24, false);
+    assert!(matches!(a, Action::SendToPty(ref v) if v == &[3]));
+}
+
 #[test]
 fn ctrl_c_in_insert_does_not_copy() {
     // In insert mode ctrl+c is sent as byte 0x03 to the PTY
     let a = handle_key_inner(&char_key("c"), true, false, false, &insert(), 80, 24, false);
     assert!(matches!(a, Action::SendToPty(ref v) if v == &[3]));
 }
 
+#[test]
+fn ctrl_c_in_normal_sends_sigint() {
+    let a = handle_key_inner(&char_key("c"), true, false, false, &normal(), 80, 24, false);
+    assert!(matches!(a, Action::SendToPty(ref v) if v == &[3]));
+}
+
+#[test]
+fn ctrl_shift_c_in_insert_does_not_copy() {
+    let a = handle_key_inner(&char_key("c"), true, true, false, &insert(), 80, 24, false);
+    assert!(!matches!(a, Action::Copy));
+}
+
+#[test]
+fn ctrl_alt_c_in_insert_does_not_copy() {
+    let a = handle_key_inner(&char_key("c"), true, false, true, &insert(), 80, 24, false);
+    assert!(!matches!(a, Action::Copy));
+}
+
 #[test]
 fn ctrl_q_quits() {
     let a = handle_key_inner(&char_key("q"), true, false, false, &insert(), 80, 24, false);