vim-patch:9.0.1227: no cmdline completion for :runtime

Problem:    No cmdline completion for :runtime.
Solution:   Add completion for :runtime. (closes vim/vim#11853, closes vim/vim#11447)
            Improve the resulting matches.

a6759381a5

src/nvim/cmdexpand.c

@@ -109,6 +109,7 @@ static bool cmdline_fuzzy_completion_supported(const expand_T *const xp)
          && xp->xp_context != EXPAND_OLD_SETTING
          && xp->xp_context != EXPAND_OWNSYNTAX
          && xp->xp_context != EXPAND_PACKADD
+         && xp->xp_context != EXPAND_RUNTIME
          && xp->xp_context != EXPAND_SHELLCMD
          && xp->xp_context != EXPAND_TAGS
          && xp->xp_context != EXPAND_TAGS_LISTFILES
@@ -1211,6 +1212,7 @@ char *addstar(char *fname, size_t len, int context)
     if (context == EXPAND_HELP
         || context == EXPAND_CHECKHEALTH
         || context == EXPAND_COLORS
+        || context == EXPAND_RUNTIME
         || context == EXPAND_COMPILER
         || context == EXPAND_OWNSYNTAX
         || context == EXPAND_FILETYPE
@@ -2072,6 +2074,11 @@ static const char *set_context_by_cmdname(const char *cmd, cmdidx_T cmdidx, expa
     xp->xp_pattern = (char *)arg;
     break;
 
+  case CMD_runtime:
+    xp->xp_context = EXPAND_RUNTIME;
+    xp->xp_pattern = (char *)arg;
+    break;
+
   case CMD_compiler:
     xp->xp_context = EXPAND_COMPILER;
     xp->xp_pattern = (char *)arg;
@@ -2712,6 +2719,11 @@ static int ExpandFromContext(expand_T *xp, char *pat, char ***matches, int *numM
     char *directories[] = { "colors", NULL };
     return ExpandRTDir(pat, DIP_START + DIP_OPT, numMatches, matches, directories);
   }
+  if (xp->xp_context == EXPAND_RUNTIME) {
+    char *directories[] = { "", NULL };
+    return ExpandRTDir(pat, DIP_START + DIP_OPT + DIP_PRNEXT, numMatches,
+                       matches, directories);
+  }
   if (xp->xp_context == EXPAND_COMPILER) {
     char *directories[] = { "compiler", NULL };
     return ExpandRTDir(pat, 0, numMatches, matches, directories);

src/nvim/runtime.c

@@ -1194,11 +1194,22 @@ int ExpandRTDir(char *pat, int flags, int *num_file, char ***file, char *dirname
 
   // TODO(bfredl): this is bullshit, expandpath should not reinvent path logic.
   for (int i = 0; dirnames[i] != NULL; i++) {
-    size_t size = strlen(dirnames[i]) + pat_len + 16;
-    char *s = xmalloc(size);
-    snprintf(s, size, "%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat);
-    globpath(p_rtp, s, &ga, 0);
-    xfree(s);
+    size_t size = strlen(dirnames[i]) + pat_len * 2 + 26;
+    char *buf = xmalloc(size);
+    if (*dirnames[i] == NUL) {
+      // empty dir used for :runtime
+      if (path_tail(pat) == pat) {
+        // no path separator, match dir names and script files
+        snprintf(buf, size, "\\(%s*.\\(vim\\|lua\\)\\)\\|\\(%s*\\)", pat, pat);
+      } else {
+        // has path separator, match script files
+        snprintf(buf, size, "%s*.vim", pat);
+      }
+    } else {
+      snprintf(buf, size, "%s/%s*.\\(vim\\|lua\\)", dirnames[i], pat);
+    }
+    globpath(p_rtp, buf, &ga, 0);
+    xfree(buf);
   }
 
   if (flags & DIP_START) {
@@ -1241,18 +1252,53 @@ int ExpandRTDir(char *pat, int flags, int *num_file, char ***file, char *dirname
     char *match = ((char **)ga.ga_data)[i];
     char *s = match;
     char *e = s + strlen(s);
+    char *res_start = s;
+    if ((flags & DIP_PRNEXT) != 0) {
+      char *p = strstr(match, pat);
+      if (p != NULL) {
+        // Drop what comes before "pat" in the match, so that for
+        // match "/long/path/syntax/cpp.vim" with pattern
+        // "syntax/cp" we only keep "syntax/cpp.vim".
+        res_start = p;
+      }
+    }
+
     if (e - s > 4 && (STRNICMP(e - 4, ".vim", 4) == 0
                       || STRNICMP(e - 4, ".lua", 4) == 0)) {
-      e -= 4;
-      for (s = e; s > match; MB_PTR_BACK(match, s)) {
-        if (vim_ispathsep(*s)) {
-          break;
+      if (res_start == s) {
+        // Only keep the file name.
+        // Remove file ext only if flag DIP_PRNEXT is not present.
+        if ((flags & DIP_PRNEXT) == 0) {
+          e -= 4;
+        }
+        for (s = e; s > match; MB_PTR_BACK(match, s)) {
+          if (s < match) {
+            break;
+          }
+          if (vim_ispathsep(*s)) {
+            res_start = s + 1;
+            break;
+          }
         }
       }
-      s++;
+
       *e = NUL;
-      assert((e - s) + 1 >= 0);
-      memmove(match, s, (size_t)(e - s) + 1);
+    }
+
+    if (res_start > match) {
+      assert((e - res_start) + 1 >= 0);
+      memmove(match, res_start, (size_t)(e - res_start) + 1);
+    }
+
+    // remove entries that look like backup files
+    if (e > s && e[-1] == '~') {
+      xfree(match);
+      char **fnames = (char **)ga.ga_data;
+      for (int j = i + 1; j < ga.ga_len; ++j) {
+        fnames[j - 1] = fnames[j];
+      }
+      ga.ga_len--;
+      i--;
     }
   }
 

src/nvim/runtime.h

@@ -105,6 +105,7 @@ typedef kvec_t(char *) CharVec;
 #define DIP_NORTP 0x20  // do not use 'runtimepath'
 #define DIP_NOAFTER 0x40  // skip "after" directories
 #define DIP_AFTER   0x80  // only use "after" directories
+#define DIP_PRNEXT  0x100       // for print also file extension
 #define DIP_DIRFILE 0x200  // find both files and directories
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS

src/nvim/testdir/test_cmdline.vim

@@ -542,6 +542,15 @@ func Test_getcompletion()
   call assert_true(index(l, '<buffer>') >= 0)
   let l = getcompletion('not', 'mapclear')
   call assert_equal([], l)
+  
+  let l = getcompletion('', 'runtime')
+  call assert_true(index(l, 'defaults.vim') >= 0)
+  let l = getcompletion('synt', 'runtime')
+  call assert_true(index(l, 'syntax') >= 0)
+  let l = getcompletion('syntax/vi', 'runtime')
+  call assert_true(index(l, 'syntax/vim.vim') >= 0)
+  let l = getcompletion('notexitsts', 'runtime')
+  call assert_equal([], l)
 
   let l = getcompletion('.', 'shellcmd')
   call assert_equal(['./', '../'], filter(l, 'v:val =~ "\\./"'))

src/nvim/usercmd.c

@@ -89,6 +89,7 @@ static const char *command_complete[] = {
   [EXPAND_SYNTIME] = "syntime",
   [EXPAND_SETTINGS] = "option",
   [EXPAND_PACKADD] = "packadd",
+  [EXPAND_RUNTIME] = "runtime",
   [EXPAND_SHELLCMD] = "shellcmd",
   [EXPAND_SIGN] = "sign",
   [EXPAND_TAGS] = "tag",

src/nvim/vim.h

@@ -156,6 +156,7 @@ enum {
   EXPAND_DIFF_BUFFERS,
   EXPAND_BREAKPOINT,
   EXPAND_SCRIPTNAMES,
+  EXPAND_RUNTIME,
   EXPAND_CHECKHEALTH,
   EXPAND_LUA,
 };