patch 8.2.0961: MS-Windows: no completion for locales

Problem:    MS-Windows: no completion for locales.
Solution:   Use the directories in $VIMRUNTIME/lang to complete locales.
            (Christian Brabandt, closes 36248)

src/cmdexpand.c

@@ -273,6 +273,7 @@ nextwild(
  * options = WILD_SILENT:	    don't print warning messages
  * options = WILD_ESCAPE:	    put backslash before special chars
  * options = WILD_ICASE:	    ignore case for files
+ * options = WILD_ALLLINKS;	    keep broken links
  *
  * The variables xp->xp_context and xp->xp_backslash must have been set!
  */

src/ex_cmds2.c

@@ -1188,7 +1188,7 @@ set_lang_var(void)
 }
 #endif
 
-#if defined(HAVE_LOCALE_H) || defined(X_LOCALE) \
+#if defined(HAVE_LOCALE_H) || defined(X_LOCALE)
 /*
  * ":language":  Set the language (locale).
  */
@@ -1321,7 +1321,6 @@ ex_language(exarg_T *eap)
 
 static char_u	**locales = NULL;	// Array of all available locales
 
-# ifndef MSWIN
 static int	did_init_locales = FALSE;
 
 /*
@@ -1333,31 +1332,87 @@ find_locales(void)
 {
     garray_T	locales_ga;
     char_u	*loc;
+    char_u	*locale_list;
+# ifdef MSWIN
+    size_t	len = 0;
+# endif
 
     // Find all available locales by running command "locale -a".  If this
     // doesn't work we won't have completion.
-    char_u *locale_a = get_cmd_output((char_u *)"locale -a",
+# ifndef MSWIN
+    locale_list = get_cmd_output((char_u *)"locale -a",
 						    NULL, SHELL_SILENT, NULL);
-    if (locale_a == NULL)
+# else
+    // Find all available locales by examining the directories in
+    // $VIMRUNTIME/lang/
+    {
+	int		options = WILD_SILENT|WILD_USE_NL|WILD_KEEP_ALL;
+	expand_T	xpc;
+	char_u		*p;
+
+	ExpandInit(&xpc);
+	xpc.xp_context = EXPAND_DIRECTORIES;
+	locale_list = ExpandOne(&xpc, (char_u *)"$VIMRUNTIME/lang/*",
+						      NULL, options, WILD_ALL);
+	ExpandCleanup(&xpc);
+	if (locale_list == NULL)
+	    // Add a dummy input, that will be skipped lated but we need to
+	    // have something in locale_list so that the C locale is added at
+	    // the end.
+	    locale_list = vim_strsave((char_u *)".\n");
+	p = locale_list;
+	// find the last directory delimiter
+	while (p != NULL && *p != NUL)
+	{
+	    if (*p == '\n')
+		break;
+	    if (*p == '\\')
+		len = p - locale_list;
+	    p++;
+	}
+    }
+# endif
+    if (locale_list == NULL)
 	return NULL;
     ga_init2(&locales_ga, sizeof(char_u *), 20);
 
-    // Transform locale_a string where each locale is separated by "\n"
+    // Transform locale_list string where each locale is separated by "\n"
     // into an array of locale strings.
-    loc = (char_u *)strtok((char *)locale_a, "\n");
+    loc = (char_u *)strtok((char *)locale_list, "\n");
 
     while (loc != NULL)
+    {
+	int ignore = FALSE;
+
+# ifdef MSWIN
+	if (len > 0)
+	    loc += len + 1;
+	// skip locales with a dot (which indicates the charset)
+	if (vim_strchr(loc, '.') != NULL)
+	    ignore = TRUE;
+# endif
+	if (!ignore)
 	{
 	    if (ga_grow(&locales_ga, 1) == FAIL)
 		break;
+
 	    loc = vim_strsave(loc);
 	    if (loc == NULL)
 		break;
 
 	    ((char_u **)locales_ga.ga_data)[locales_ga.ga_len++] = loc;
+	}
 	loc = (char_u *)strtok(NULL, "\n");
     }
-    vim_free(locale_a);
+
+# ifdef MSWIN
+    // Add the C locale
+    if (ga_grow(&locales_ga, 1) == OK)
+	((char_u **)locales_ga.ga_data)[locales_ga.ga_len++] =
+						    vim_strsave((char_u *)"C");
+# endif
+
+    vim_free(locale_list);
     if (ga_grow(&locales_ga, 1) == FAIL)
     {
 	ga_clear(&locales_ga);
@@ -1366,7 +1421,6 @@ find_locales(void)
     ((char_u **)locales_ga.ga_data)[locales_ga.ga_len] = NULL;
     return (char_u **)locales_ga.ga_data;
 }
-# endif
 
 /*
  * Lazy initialization of all available locales.
@@ -1374,13 +1428,11 @@ find_locales(void)
     static void
 init_locales(void)
 {
-#  ifndef MSWIN
     if (!did_init_locales)
     {
 	did_init_locales = TRUE;
 	locales = find_locales();
     }
-#  endif
 }
 
 # if defined(EXITFREE) || defined(PROTO)

src/testdir/test_cmdline.vim

@@ -609,9 +609,6 @@ func Test_cmdline_complete_languages()
   call feedkeys(":language \<c-a>\<c-b>\"\<cr>", 'tx')
   call assert_match('^"language .*\<ctype\>.*\<messages\>.*\<time\>', @:)
 
-  if has('unix')
-    " TODO: these tests don't work on Windows. lang appears to be 'C'
-    " but C does not appear in the completion. Why?
   call assert_match('^"language .*\<' . lang . '\>', @:)
 
   call feedkeys(":language messages \<c-a>\<c-b>\"\<cr>", 'tx')
@@ -622,7 +619,6 @@ func Test_cmdline_complete_languages()
 
   call feedkeys(":language time \<c-a>\<c-b>\"\<cr>", 'tx')
   call assert_match('^"language .*\<' . lang . '\>', @:)
-  endif
 endfunc
 
 func Test_cmdline_complete_env_variable()

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    961,
 /**/
     960,
 /**/