vim-patch:9.1.0495: Matched text isn't highlighted in cmdline pum

Problem:  Matched text isn't highlighted in cmdline pum.
Solution: Use cmdline completion pattern in cmdline mode.
          (zeertzjq)

closes: vim/vim#15029

https://github.com/vim/vim/commit/d8c9340fc67ca19f82ec3e77ec38296424e758cf

Cherry-pick syntax.txt change from runtime update.

2 files changed, 23 insertions, 4 deletions

diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index f75b84c77b..9ee5cde5b2 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -402,6 +402,20 @@ void cmdline_pum_cleanup(CmdlineInfo *cclp)
   wildmenu_cleanup(cclp);
 }
 
+/// Returns the current cmdline completion pattern.
+char *cmdline_compl_pattern(void)
+{
+  expand_T *xp = get_cmdline_info()->xpc;
+  return xp == NULL ? NULL : xp->xp_orig;
+}
+
+/// Returns true if fuzzy cmdline completion is active, false otherwise.
+bool cmdline_compl_is_fuzzy(void)
+{
+  expand_T *xp = get_cmdline_info()->xpc;
+  return xp != NULL && cmdline_fuzzy_completion_supported(xp);
+}
+
 /// Return the number of characters that should be skipped in the wildmenu
 /// These are backslashes used for escaping.  Do show backslashes in help tags.
 static int skip_wildmenu_char(expand_T *xp, char *s)
diff --git a/src/nvim/popupmenu.c b/src/nvim/popupmenu.c
index 18446e749b..2d3c128de1 100644
--- a/src/nvim/popupmenu.c
+++ b/src/nvim/popupmenu.c
@@ -17,6 +17,7 @@
 #include "nvim/buffer_updates.h"
 #include "nvim/change.h"
 #include "nvim/charset.h"
+#include "nvim/cmdexpand.h"
 #include "nvim/drawscreen.h"
 #include "nvim/edit.h"
 #include "nvim/errors.h"
@@ -441,17 +442,21 @@ void pum_display(pumitem_T *array, int size, int selected, bool array_changed, i
 /// Returns attributes for every cell, or NULL if all attributes are the same.
 static int *pum_compute_text_attrs(char *text, hlf_T hlf)
 {
-  char *leader = ins_compl_leader();
-
-  if (leader == NULL || *leader == NUL || (hlf != HLF_PSI && hlf != HLF_PNI)
+  if ((hlf != HLF_PSI && hlf != HLF_PNI)
       || (win_hl_attr(curwin, HLF_PMSI) == win_hl_attr(curwin, HLF_PSI)
           && win_hl_attr(curwin, HLF_PMNI) == win_hl_attr(curwin, HLF_PNI))) {
     return NULL;
   }
 
+  char *leader = State == MODE_CMDLINE ? cmdline_compl_pattern() : ins_compl_leader();
+  if (leader == NULL || *leader == NUL) {
+    return NULL;
+  }
+
   int *attrs = xmalloc(sizeof(int) * (size_t)vim_strsize(text));
+  bool in_fuzzy = State == MODE_CMDLINE ? cmdline_compl_is_fuzzy()
+                                        : (get_cot_flags() & COT_FUZZY) != 0;
   size_t leader_len = strlen(leader);
-  const bool in_fuzzy = (get_cot_flags() & COT_FUZZY) != 0;
 
   garray_T *ga = NULL;
   bool matched_start = false;