vim-patch:9.1.1247: fragile setup to get (preferred) keys from key_name_entry (#33102)

Problem:  fragile setup to get (preferred) keys from key_name_entry
          (after v9.1.1179)
Solution: refactor the code further, fix a bug with "pref_name" key
          entry introduced in v9.1.1180 (Yee Cheng Chin)

The optimization introduced for using bsearch() with key_name_entry
in vim/vim#16788 was fragile as it required synchronizing a non-obvious index
(e.g. IDX_KEYNAME_SWU) with the array that could be accidentally changed
by any one adding a key to it. Furthermore, the "pref_name" that was
introduced in that change was unnecessary, and in fact introduced a bug,
as we don't always want to use the canonical name.

The bug is triggered when the user triggers auto-complete using a
keycode, such as `:set <Scroll<Tab>`. The bug would end up showing two
copies of `<ScrollWheelUp>` because both entries end up using the
canonical name.

In this change, remove `pref_name`, and simply use a boolean to track
whether an entry is an alt name or not and modify logic to respect that.

Add test to make sure auto-complete works with alt names

closes: vim/vim#16987

https://github.com/vim/vim/commit/7d8e7df55190e8e4e5a66f443e4440b52edf2fdb

In Nvim there is no `enabled` field, so put `is_alt` before `name` to
reduce the size of the struct.

Co-authored-by: Yee Cheng Chin <ychin.git@gmail.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/src/nvim/keycodes.c b/src/nvim/keycodes.c
index 9cb2321eee..778682a881 100644
--- a/src/nvim/keycodes.c
+++ b/src/nvim/keycodes.c
@@ -338,10 +338,7 @@ char *get_special_key_name(int c, int modifiers)
       }
     }
   } else {            // use name of special key
-    const String *s = key_names_table[table_idx].pref_name != NULL
-                      ? key_names_table[table_idx].pref_name
-                      : &key_names_table[table_idx].name;
-
+    const String *s = &key_names_table[table_idx].name;
     if ((int)s->size + idx + 2 <= MAX_KEY_NAME_LEN) {
       STRCPY(string + idx, s->data);
       idx += (int)s->size;
@@ -593,7 +590,7 @@ static int extract_modifiers(int key, int *modp, const bool simplify, bool *cons
 int find_special_key_in_table(int c)
 {
   for (int i = 0; i < (int)ARRAY_SIZE(key_names_table); i++) {
-    if (c == key_names_table[i].key) {
+    if (c == key_names_table[i].key && !key_names_table[i].is_alt) {
       return i;
     }
   }