vim-patch:9.1.0010: Keymap completion is not available (#26888)

Problem:  Keymap completion is not available
Solution: Add keymap completion (Doug Kearns)

Add keymap completion to the 'keymap' option, user commands and builtin
completion functions.

closes: vim/vim#13692

81642d9d6f

Co-authored-by: Doug Kearns <dougkearns@gmail.com>

src/nvim/cmdexpand.c

@@ -99,6 +99,7 @@ static bool cmdline_fuzzy_completion_supported(const expand_T *const xp)
          && xp->xp_context != EXPAND_FILES_IN_PATH
          && xp->xp_context != EXPAND_FILETYPE
          && xp->xp_context != EXPAND_HELP
+         && xp->xp_context != EXPAND_KEYMAP
          && xp->xp_context != EXPAND_LUA
          && xp->xp_context != EXPAND_OLD_SETTING
          && xp->xp_context != EXPAND_STRING_SETTING
@@ -1215,6 +1216,7 @@ char *addstar(char *fname, size_t len, int context)
         || context == EXPAND_COMPILER
         || context == EXPAND_OWNSYNTAX
         || context == EXPAND_FILETYPE
+        || context == EXPAND_KEYMAP
         || context == EXPAND_PACKADD
         || context == EXPAND_RUNTIME
         || ((context == EXPAND_TAGS_LISTFILES || context == EXPAND_TAGS)
@@ -2741,6 +2743,10 @@ static int ExpandFromContext(expand_T *xp, char *pat, char ***matches, int *numM
     char *directories[] = { "syntax", "indent", "ftplugin", NULL };
     return ExpandRTDir(pat, 0, numMatches, matches, directories);
   }
+  if (xp->xp_context == EXPAND_KEYMAP) {
+    char *directories[] = { "keymap", NULL };
+    return ExpandRTDir(pat, 0, numMatches, matches, directories);
+  }
   if (xp->xp_context == EXPAND_USER_LIST) {
     return ExpandUserList(xp, matches, numMatches);
   }

src/nvim/cmdexpand_defs.h

@@ -105,6 +105,7 @@ enum {
   EXPAND_STRING_SETTING,
   EXPAND_SETTING_SUBTRACT,
   EXPAND_ARGOPT,
+  EXPAND_KEYMAP,
   EXPAND_CHECKHEALTH,
   EXPAND_LUA,
 };

src/nvim/eval.lua

@@ -3609,6 +3609,7 @@ M.funcs = {
       help		help subjects
       highlight	highlight groups
       history		|:history| suboptions
+      keymap		keyboard mappings
       locale		locale names (as output of locale -a)
       mapclear	buffer argument
       mapping		mapping name

src/nvim/option.c

@@ -5461,6 +5461,10 @@ void set_context_in_set_cmd(expand_T *xp, char *arg, int opt_flags)
     xp->xp_context = EXPAND_FILETYPE;
     return;
   }
+  if (options[opt_idx].var == &p_keymap) {
+    xp->xp_context = EXPAND_KEYMAP;
+    return;
+  }
 
   // Now pick. If the option has a custom expander, use that. Otherwise, just
   // fill with the existing option value.

src/nvim/usercmd.c

@@ -75,6 +75,7 @@ static const char *command_complete[] = {
   [EXPAND_HELP] = "help",
   [EXPAND_HIGHLIGHT] = "highlight",
   [EXPAND_HISTORY] = "history",
+  [EXPAND_KEYMAP] = "keymap",
 #ifdef HAVE_WORKING_LIBINTL
   [EXPAND_LOCALES] = "locale",
 #endif