feat(terminal): add support for kitty keyboard protocol

This commit adds basic support for the kitty keyboard protocol to
Neovim's builtin terminal. For now only the first mode ("Disambiguate
escape codes") is supported.

1 files changed, 10 insertions, 6 deletions

diff --git a/src/nvim/getchar.c b/src/nvim/getchar.c
index 6cf4556a9f..6ec84ff543 100644
--- a/src/nvim/getchar.c
+++ b/src/nvim/getchar.c
@@ -1517,12 +1517,10 @@ int merge_modifiers(int c_arg, int *modifiers)
   int c = c_arg;
 
   if (*modifiers & MOD_MASK_CTRL) {
-    if ((c >= '`' && c <= 0x7f) || (c >= '@' && c <= '_')) {
-      if (!(State & MODE_TERMINAL) || !(c == 'I' || c == 'J' || c == 'M' || c == '[')) {
-        c &= 0x1f;
-        if (c == NUL) {
-          c = K_ZERO;
-        }
+    if (c >= '@' && c <= 0x7f) {
+      c &= 0x1f;
+      if (c == NUL) {
+        c = K_ZERO;
       }
     } else if (c == '6') {
       // CTRL-6 is equivalent to CTRL-^
@@ -2058,6 +2056,12 @@ static bool at_ins_compl_key(void)
 /// @return  the length of the replaced bytes, 0 if nothing changed, -1 for error.
 static int check_simplify_modifier(int max_offset)
 {
+  // We want full modifiers in Terminal mode so that the key can be correctly
+  // encoded
+  if (State & MODE_TERMINAL) {
+    return 0;
+  }
+
   for (int offset = 0; offset < max_offset; offset++) {
     if (offset + 3 >= typebuf.tb_len) {
       break;