patch 8.2.4465: fuzzy completion does not order matches properly

Problem:    Fuzzy completion does not order matches properly.
Solution:   Do not use regular expression match. (Yegappan Lakshmanan,
            closes #9843)

src/cmdexpand.c

@@ -2633,6 +2633,7 @@ ExpandGeneric(
     int			score = 0;
     int		fuzzy = (fuzzystr != NULL);
     int		funcsort = FALSE;
+    int		match;
 
     // do this loop twice:
     // round == 0: count the number of matching names
@@ -2647,9 +2648,17 @@ ExpandGeneric(
 	    if (*str == NUL)	    // skip empty strings
 		continue;
 
-	    if (vim_regexec(regmatch, str, (colnr_T)0) ||
+	    if (!fuzzy)
-		    (fuzzy && ((score = fuzzy_match_str(str, fuzzystr)) != 0)))
+	       match = vim_regexec(regmatch, str, (colnr_T)0);
+	    else
 	    {
+		score = fuzzy_match_str(str, fuzzystr);
+		match = (score != 0);
+	    }
+
+	    if (!match)
+		continue;
+
 	    if (round)
 	    {
 		if (escaped)
@@ -2658,9 +2667,10 @@ ExpandGeneric(
 		    str = vim_strsave(str);
 		if (str == NULL)
 		{
-			FreeWild(count, *matches);
 		    if (fuzzy)
 			fuzmatch_str_free(fuzmatch, count);
+		    else if (count > 0)
+			FreeWild(count, *matches);
 		    *numMatches = 0;
 		    *matches = NULL;
 		    return FAIL;
@@ -2685,7 +2695,6 @@ ExpandGeneric(
 	    }
 	    ++count;
 	}
-	}
 	if (round == 0)
 	{
 	    if (count == 0)

src/search.c

@@ -5001,7 +5001,7 @@ fuzzy_match_func_sort(fuzmatch_str_T *fm, int sz)
 fuzzy_match_str(char_u *str, char_u *pat)
 {
     int		score = 0;
-    int_u	matchpos[256];
+    int_u	matchpos[MAX_FUZZY_MATCHES];
 
     if (str == NULL || pat == NULL)
 	return 0;

src/testdir/test_cmdline.vim

@@ -2757,6 +2757,25 @@ func Test_wildoptions_fuzzy()
   call feedkeys(":let SVar\<Tab>\<C-B>\"\<CR>", 'tx')
   call assert_equal('"let SomeVariable', @:)
 
+  " Test for sorting the results by the best match
+  %bw!
+  command T123format :
+  command T123goformat :
+  command T123TestFOrmat :
+  command T123fendoff :
+  command T123state :
+  command T123FendingOff :
+  set wildoptions=fuzzy
+  call feedkeys(":T123fo\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"T123format T123TestFOrmat T123FendingOff T123goformat T123fendoff', @:)
+  delcommand T123format
+  delcommand T123goformat
+  delcommand T123TestFOrmat
+  delcommand T123fendoff
+  delcommand T123state
+  delcommand T123FendingOff
+  %bw
+
   set wildoptions&
   %bw!
 endfunc

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4465,
 /**/
     4464,
 /**/