patch 8.2.4463: completion only uses strict matchingv8.2.4463

Problem:    Completion only uses strict matching.
Solution:   Add the "fuzzy" item for 'wildoptions'. (Yegappan Lakshmanan,
            closes #9803)

13 files changed, 842 insertions, 117 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 27e8643870..e580874906 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2728,10 +2728,12 @@ ExpandBufnames(
     int		round;
     char_u	*p;
     int		attempt;
-    char_u	*patc;
+    char_u	*patc = NULL;
 #ifdef FEAT_VIMINFO
     bufmatch_T	*matches = NULL;
 #endif
+    int		fuzzy;
+    fuzmatch_str_T  *fuzmatch = NULL;
 
     *num_file = 0;		    // return values in case of FAIL
     *file = NULL;
@@ -2741,32 +2743,42 @@ ExpandBufnames(
 	return FAIL;
 #endif
 
-    // Make a copy of "pat" and change "^" to "\(^\|[\/]\)".
-    if (*pat == '^')
+    fuzzy = cmdline_fuzzy_complete(pat);
+
+    // Make a copy of "pat" and change "^" to "\(^\|[\/]\)" (if doing regular
+    // expression matching)
+    if (!fuzzy)
     {
-	patc = alloc(STRLEN(pat) + 11);
-	if (patc == NULL)
-	    return FAIL;
-	STRCPY(patc, "\\(^\\|[\\/]\\)");
-	STRCPY(patc + 11, pat + 1);
+	if (*pat == '^')
+	{
+	    patc = alloc(STRLEN(pat) + 11);
+	    if (patc == NULL)
+		return FAIL;
+	    STRCPY(patc, "\\(^\\|[\\/]\\)");
+	    STRCPY(patc + 11, pat + 1);
+	}
+	else
+	    patc = pat;
     }
-    else
-	patc = pat;
 
     // attempt == 0: try match with    '\<', match at start of word
     // attempt == 1: try match without '\<', match anywhere
-    for (attempt = 0; attempt <= 1; ++attempt)
+    for (attempt = 0; attempt <= (fuzzy ? 0 : 1); ++attempt)
     {
 	regmatch_T	regmatch;
+	int		score = 0;
 
-	if (attempt > 0 && patc == pat)
-	    break;	// there was no anchor, no need to try again
-	regmatch.regprog = vim_regcomp(patc + attempt * 11, RE_MAGIC);
-	if (regmatch.regprog == NULL)
+	if (!fuzzy)
 	{
-	    if (patc != pat)
-		vim_free(patc);
-	    return FAIL;
+	    if (attempt > 0 && patc == pat)
+		break;	// there was no anchor, no need to try again
+	    regmatch.regprog = vim_regcomp(patc + attempt * 11, RE_MAGIC);
+	    if (regmatch.regprog == NULL)
+	    {
+		if (patc != pat)
+		    vim_free(patc);
+		return FAIL;
+	    }
 	}
 
 	// round == 1: Count the matches.
@@ -2786,7 +2798,22 @@ ExpandBufnames(
 			continue;
 #endif
 
-		p = buflist_match(&regmatch, buf, p_wic);
+		if (!fuzzy)
+		    p = buflist_match(&regmatch, buf, p_wic);
+		else
+		{
+		    p = NULL;
+		    // first try matching with the short file name
+		    if ((score = fuzzy_match_str(buf->b_sfname, pat)) != 0)
+			p = buf->b_sfname;
+		    if (p == NULL)
+		    {
+			// next try matching with the full path file name
+			if ((score = fuzzy_match_str(buf->b_ffname, pat)) != 0)
+			    p = buf->b_ffname;
+		    }
+		}
+
 		if (p != NULL)
 		{
 		    if (round == 1)
@@ -2797,16 +2824,27 @@ ExpandBufnames(
 			    p = home_replace_save(buf, p);
 			else
 			    p = vim_strsave(p);
+
+			if (!fuzzy)
+			{
 #ifdef FEAT_VIMINFO
-			if (matches != NULL)
+			    if (matches != NULL)
+			    {
+				matches[count].buf = buf;
+				matches[count].match = p;
+				count++;
+			    }
+			    else
+#endif
+				(*file)[count++] = p;
+			}
+			else
 			{
-			    matches[count].buf = buf;
-			    matches[count].match = p;
+			    fuzmatch[count].idx = count;
+			    fuzmatch[count].str = p;
+			    fuzmatch[count].score = score;
 			    count++;
 			}
-			else
-#endif
-			    (*file)[count++] = p;
 		    }
 		}
 	    }
@@ -2814,47 +2852,72 @@ ExpandBufnames(
 		break;
 	    if (round == 1)
 	    {
-		*file = ALLOC_MULT(char_u *, count);
-		if (*file == NULL)
+		if (!fuzzy)
 		{
-		    vim_regfree(regmatch.regprog);
-		    if (patc != pat)
-			vim_free(patc);
-		    return FAIL;
-		}
+		    *file = ALLOC_MULT(char_u *, count);
+		    if (*file == NULL)
+		    {
+			vim_regfree(regmatch.regprog);
+			if (patc != pat)
+			    vim_free(patc);
+			return FAIL;
+		    }
 #ifdef FEAT_VIMINFO
-		if (options & WILD_BUFLASTUSED)
-		    matches = ALLOC_MULT(bufmatch_T, count);
+		    if (options & WILD_BUFLASTUSED)
+			matches = ALLOC_MULT(bufmatch_T, count);
 #endif
+		}
+		else
+		{
+		    fuzmatch = ALLOC_MULT(fuzmatch_str_T, count);
+		    if (fuzmatch == NULL)
+		    {
+			*num_file = 0;
+			*file = NULL;
+			return FAIL;
+		    }
+		}
 	    }
 	}
-	vim_regfree(regmatch.regprog);
-	if (count)		// match(es) found, break here
-	    break;
+
+	if (!fuzzy)
+	{
+	    vim_regfree(regmatch.regprog);
+	    if (count)		// match(es) found, break here
+		break;
+	}
     }
 
-    if (patc != pat)
+    if (!fuzzy && patc != pat)
 	vim_free(patc);
 
 #ifdef FEAT_VIMINFO
-    if (matches != NULL)
+    if (!fuzzy)
     {
-	int i;
-	if (count > 1)
-	    qsort(matches, count, sizeof(bufmatch_T), buf_compare);
-	// if the current buffer is first in the list, place it at the end
-	if (matches[0].buf == curbuf)
+	if (matches != NULL)
 	{
-	    for (i = 1; i < count; i++)
-		(*file)[i-1] = matches[i].match;
-	    (*file)[count-1] = matches[0].match;
-	}
-	else
-	{
-	    for (i = 0; i < count; i++)
-		(*file)[i] = matches[i].match;
+	    int i;
+	    if (count > 1)
+		qsort(matches, count, sizeof(bufmatch_T), buf_compare);
+	    // if the current buffer is first in the list, place it at the end
+	    if (matches[0].buf == curbuf)
+	    {
+		for (i = 1; i < count; i++)
+		    (*file)[i-1] = matches[i].match;
+		(*file)[count-1] = matches[0].match;
+	    }
+	    else
+	    {
+		for (i = 0; i < count; i++)
+		    (*file)[i] = matches[i].match;
+	    }
+	    vim_free(matches);
 	}
-	vim_free(matches);
+    }
+    else
+    {
+	if (fuzzymatches_to_strmatches(fuzmatch, file, count, FALSE) == FAIL)
+	    return FAIL;
     }
 #endif
 
diff --git a/src/cmdexpand.c b/src/cmdexpand.c
index 2e4a0ebdee..909706d1de 100644
--- a/src/cmdexpand.c
+++ b/src/cmdexpand.c
@@ -18,7 +18,8 @@ static int	cmd_showtail;	// Only show path tail in lists ?
 static void	set_expand_context(expand_T *xp);
 static int      ExpandGeneric(expand_T *xp, regmatch_T *regmatch,
 			      char_u ***matches, int *numMatches,
-			      char_u *((*func)(expand_T *, int)), int escaped);
+			      char_u *((*func)(expand_T *, int)), int escaped,
+			      char_u *fuzzystr);
 static int	ExpandFromContext(expand_T *xp, char_u *, char_u ***, int *, int);
 static int	expand_showtail(expand_T *xp);
 static int	expand_shellcmd(char_u *filepat, char_u ***matches, int *numMatches, int flagsarg);
@@ -40,6 +41,43 @@ static int compl_selected;
 #define SHOW_FILE_TEXT(m) (showtail ? sm_gettail(matches[m]) : matches[m])
 
 /*
+ * Returns TRUE if fuzzy completion is supported for a given cmdline completion
+ * context.
+ */
+    static int
+cmdline_fuzzy_completion_supported(expand_T *xp)
+{
+    return (vim_strchr(p_wop, WOP_FUZZY) != NULL
+	    && xp->xp_context != EXPAND_BOOL_SETTINGS
+	    && xp->xp_context != EXPAND_COLORS
+	    && xp->xp_context != EXPAND_COMPILER
+	    && xp->xp_context != EXPAND_DIRECTORIES
+	    && xp->xp_context != EXPAND_FILES
+	    && xp->xp_context != EXPAND_FILES_IN_PATH
+	    && xp->xp_context != EXPAND_FILETYPE
+	    && xp->xp_context != EXPAND_HELP
+	    && xp->xp_context != EXPAND_MAPPINGS
+	    && xp->xp_context != EXPAND_OLD_SETTING
+	    && xp->xp_context != EXPAND_OWNSYNTAX
+	    && xp->xp_context != EXPAND_PACKADD
+	    && xp->xp_context != EXPAND_SHELLCMD
+	    && xp->xp_context != EXPAND_TAGS
+	    && xp->xp_context != EXPAND_TAGS_LISTFILES
+	    && xp->xp_context != EXPAND_USER_DEFINED
+	    && xp->xp_context != EXPAND_USER_LIST);
+}
+
+/*
+ * Returns TRUE if fuzzy completion for cmdline completion is enabled and
+ * 'fuzzystr' is not empty.
+ */
+    int
+cmdline_fuzzy_complete(char_u *fuzzystr)
+{
+    return vim_strchr(p_wop, WOP_FUZZY) != NULL && *fuzzystr != NUL;
+}
+
+/*
  * sort function for the completion matches.
  * <SNR> functions should be sorted to the end.
  */
@@ -195,9 +233,14 @@ nextwild(
     }
     else
     {
+	if (cmdline_fuzzy_completion_supported(xp))
+	    // If fuzzy matching, don't modify the search string
+	    p1 = vim_strsave(xp->xp_pattern);
+	else
+	    p1 = addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
+
 	// Translate string into pattern and expand it.
-	if ((p1 = addstar(xp->xp_pattern, xp->xp_pattern_len,
-						     xp->xp_context)) == NULL)
+	if (p1 == NULL)
 	    p2 = NULL;
 	else
 	{
@@ -2188,9 +2231,15 @@ expand_cmdline(
 
     // add star to file name, or convert to regexp if not exp. files.
     xp->xp_pattern_len = (int)(str + col - xp->xp_pattern);
-    file_str = addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
-    if (file_str == NULL)
-	return EXPAND_UNSUCCESSFUL;
+    if (cmdline_fuzzy_completion_supported(xp))
+	// If fuzzy matching, don't modify the search string
+	file_str = vim_strsave(xp->xp_pattern);
+    else
+    {
+	file_str = addstar(xp->xp_pattern, xp->xp_pattern_len, xp->xp_context);
+	if (file_str == NULL)
+	    return EXPAND_UNSUCCESSFUL;
+    }
 
     if (p_wic)
 	options += WILD_ICASE;
@@ -2317,6 +2366,7 @@ get_mapclear_arg(expand_T *xp UNUSED, int idx)
  */
     static int
 ExpandOther(
+	char_u		*pat,
 	expand_T	*xp, 
 	regmatch_T	*rmp,
 	char_u		***matches,
@@ -2386,10 +2436,16 @@ ExpandOther(
     {
 	if (xp->xp_context == tab[i].context)
 	{
+	    // Use fuzzy matching if 'wildoptions' has 'fuzzy'.
+	    // If no search pattern is supplied, then don't use fuzzy
+	    // matching and return all the found items.
+	    int fuzzy = cmdline_fuzzy_complete(pat);
+
 	    if (tab[i].ic)
 		rmp->rm_ic = TRUE;
 	    ret = ExpandGeneric(xp, rmp, matches, numMatches,
-						tab[i].func, tab[i].escaped);
+						tab[i].func, tab[i].escaped,
+						fuzzy ? pat : NULL);
 	    break;
 	}
     }
@@ -2530,7 +2586,7 @@ ExpandFromContext(
 
     if (xp->xp_context == EXPAND_SETTINGS
 	    || xp->xp_context == EXPAND_BOOL_SETTINGS)
-	ret = ExpandSettings(xp, &regmatch, numMatches, matches);
+	ret = ExpandSettings(xp, &regmatch, pat, numMatches, matches);
     else if (xp->xp_context == EXPAND_MAPPINGS)
 	ret = ExpandMappings(&regmatch, numMatches, matches);
 # if defined(FEAT_EVAL)
@@ -2538,7 +2594,7 @@ ExpandFromContext(
 	ret = ExpandUserDefined(xp, &regmatch, matches, numMatches);
 # endif
     else
-	ret = ExpandOther(xp, &regmatch, matches, numMatches);
+	ret = ExpandOther(pat, xp, &regmatch, matches, numMatches);
 
     vim_regfree(regmatch.regprog);
     vim_free(tofree);
@@ -2553,6 +2609,9 @@ ExpandFromContext(
  * obtain strings, one by one.	The strings are matched against a regexp
  * program.  Matching strings are copied into an array, which is returned.
  *
+ * If 'fuzzy' is TRUE, then fuzzy matching is used. Otherwise, regex matching
+ * is used.
+ *
  * Returns OK when no problems encountered, FAIL for error (out of memory).
  */
     static int
@@ -2563,12 +2622,17 @@ ExpandGeneric(
     int		*numMatches,
     char_u	*((*func)(expand_T *, int)),
 					  // returns a string from the list
-    int		escaped)
+    int		escaped,
+    char_u	*fuzzystr)
 {
     int		i;
     int		count = 0;
     int		round;
     char_u	*str;
+    fuzmatch_str_T	*fuzmatch = NULL;
+    int			score = 0;
+    int		fuzzy = (fuzzystr != NULL);
+    int		funcsort = FALSE;
 
     // do this loop twice:
     // round == 0: count the number of matching names
@@ -2583,7 +2647,8 @@ ExpandGeneric(
 	    if (*str == NUL)	    // skip empty strings
 		continue;
 
-	    if (vim_regexec(regmatch, str, (colnr_T)0))
+	    if (vim_regexec(regmatch, str, (colnr_T)0) ||
+		    (fuzzy && ((score = fuzzy_match_str(str, fuzzystr)) != 0)))
 	    {
 		if (round)
 		{
@@ -2594,11 +2659,20 @@ ExpandGeneric(
 		    if (str == NULL)
 		    {
 			FreeWild(count, *matches);
+			if (fuzzy)
+			    fuzmatch_str_free(fuzmatch, count);
 			*numMatches = 0;
 			*matches = NULL;
 			return FAIL;
 		    }
-		    (*matches)[count] = str;
+		    if (fuzzy)
+		    {
+			fuzmatch[count].idx = count;
+			fuzmatch[count].str = str;
+			fuzmatch[count].score = score;
+		    }
+		    else
+			(*matches)[count] = str;
 # ifdef FEAT_MENU
 		    if (func == get_menu_names && str != NULL)
 		    {
@@ -2616,8 +2690,11 @@ ExpandGeneric(
 	{
 	    if (count == 0)
 		return OK;
-	    *matches = ALLOC_MULT(char_u *, count);
-	    if (*matches == NULL)
+	    if (fuzzy)
+		fuzmatch = ALLOC_MULT(fuzmatch_str_T, count);
+	    else
+		*matches = ALLOC_MULT(char_u *, count);
+	    if ((fuzzy && (fuzmatch == NULL)) || (*matches == NULL))
 	    {
 		*numMatches = 0;
 		*matches = NULL;
@@ -2635,11 +2712,18 @@ ExpandGeneric(
 		|| xp->xp_context == EXPAND_FUNCTIONS
 		|| xp->xp_context == EXPAND_USER_FUNC
 		|| xp->xp_context == EXPAND_DISASSEMBLE)
+	{
 	    // <SNR> functions should be sorted to the end.
-	    qsort((void *)*matches, (size_t)*numMatches, sizeof(char_u *),
+	    funcsort = TRUE;
+	    if (!fuzzy)
+		qsort((void *)*matches, (size_t)*numMatches, sizeof(char_u *),
 							   sort_func_compare);
+	}
 	else
-	    sort_strings(*matches, *numMatches);
+	{
+	    if (!fuzzy)
+		sort_strings(*matches, *numMatches);
+	}
     }
 
 #if defined(FEAT_SYN_HL)
@@ -2647,6 +2731,11 @@ ExpandGeneric(
     // they don't show up when getting normal highlight names by ID.
     reset_expand_highlight();
 #endif
+
+    if (fuzzy && fuzzymatches_to_strmatches(fuzmatch, matches, count,
+							funcsort) == FAIL)
+	return FAIL;
+
     return OK;
 }
 
diff --git a/src/option.c b/src/option.c
index 44a0520ad0..936906649d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -6447,12 +6447,70 @@ set_context_in_set_cmd(
     }
 }
 
+/*
+ * Returns TRUE if 'str' either matches 'regmatch' or fuzzy matches 'pat'.
+ *
+ * If 'test_only' is TRUE and 'fuzzy' is FALSE and if 'str' matches the regular
+ * expression 'regmatch', then returns TRUE.  Otherwise returns FALSE.
+ *
+ * If 'test_only' is FALSE and 'fuzzy' is FALSE and if 'str' matches the
+ * regular expression 'regmatch', then stores the match in matches[idx] and
+ * returns TRUE.
+ *
+ * If 'test_only' is TRUE and 'fuzzy' is TRUE and if 'str' fuzzy matches
+ * 'fuzzystr', then returns TRUE. Otherwise returns FALSE.
+ *
+ * If 'test_only' is FALSE and 'fuzzy' is TRUE and if 'str' fuzzy matches
+ * 'fuzzystr', then stores the match details in fuzmatch[idx] and returns TRUE.
+ */
+    static int
+match_str(
+	char_u		*str,
+	regmatch_T	*regmatch,
+	char_u		**matches,
+	int		idx,
+	int		test_only,
+	int		fuzzy,
+	char_u		*fuzzystr,
+	fuzmatch_str_T  *fuzmatch)
+{
+    if (!fuzzy)
+    {
+	if (vim_regexec(regmatch, str, (colnr_T)0))
+	{
+	    if (!test_only)
+		matches[idx] = vim_strsave(str);
+	    return TRUE;
+	}
+    }
+    else
+    {
+	int score;
+
+	score = fuzzy_match_str(str, fuzzystr);
+	if (score != 0)
+	{
+	    if (!test_only)
+	    {
+		fuzmatch[idx].idx = idx;
+		fuzmatch[idx].str = vim_strsave(str);
+		fuzmatch[idx].score = score;
+	    }
+
+	    return TRUE;
+	}
+    }
+
+    return FALSE;
+}
+
     int
 ExpandSettings(
     expand_T	*xp,
     regmatch_T	*regmatch,
-    int		*num_file,
-    char_u	***file)
+    char_u	*fuzzystr,
+    int		*numMatches,
+    char_u	***matches)
 {
     int		num_normal = 0;	    // Nr of matching non-term-code settings
     int		num_term = 0;	    // Nr of matching terminal code settings
@@ -6465,6 +6523,10 @@ ExpandSettings(
     char_u	name_buf[MAX_KEY_NAME_LEN];
     static char *(names[]) = {"all", "termcap"};
     int		ic = regmatch->rm_ic;	// remember the ignore-case flag
+    int		fuzzy;
+    fuzmatch_str_T  *fuzmatch = NULL;
+
+    fuzzy = cmdline_fuzzy_complete(fuzzystr);
 
     // do this loop twice:
     // loop == 0: count the number of matching options
@@ -6475,13 +6537,16 @@ ExpandSettings(
 	if (xp->xp_context != EXPAND_BOOL_SETTINGS)
 	{
 	    for (match = 0; match < (int)ARRAY_LENGTH(names); ++match)
-		if (vim_regexec(regmatch, (char_u *)names[match], (colnr_T)0))
+	    {
+		if (match_str((char_u *)names[match], regmatch, *matches,
+			    count, (loop == 0), fuzzy, fuzzystr, fuzmatch))
 		{
 		    if (loop == 0)
 			num_normal++;
 		    else
-			(*file)[count++] = vim_strsave((char_u *)names[match]);
+			count++;
 		}
+	    }
 	}
 	for (opt_idx = 0; (str = (char_u *)options[opt_idx].fullname) != NULL;
 								    opt_idx++)
@@ -6494,12 +6559,37 @@ ExpandSettings(
 	    is_term_opt = istermoption_idx(opt_idx);
 	    if (is_term_opt && num_normal > 0)
 		continue;
-	    match = FALSE;
-	    if (vim_regexec(regmatch, str, (colnr_T)0)
-		    || (options[opt_idx].shortname != NULL
+
+	    if (match_str(str, regmatch, *matches, count, (loop == 0),
+						fuzzy, fuzzystr, fuzmatch))
+	    {
+		if (loop == 0)
+		{
+		    if (is_term_opt)
+			num_term++;
+		    else
+			num_normal++;
+		}
+		else
+		    count++;
+	    }
+	    else if (!fuzzy && options[opt_idx].shortname != NULL
 			&& vim_regexec(regmatch,
-			   (char_u *)options[opt_idx].shortname, (colnr_T)0)))
-		match = TRUE;
+                             (char_u *)options[opt_idx].shortname, (colnr_T)0))
+	    {
+		// Compare against the abbreviated option name (for regular
+		// expression match). Fuzzy matching (previous if) already
+		// matches against both the expanded and abbreviated names.
+		if (loop == 0)
+		{
+		    if (is_term_opt)
+			num_term++;
+		    else
+			num_normal++;
+		}
+		else
+		    (*matches)[count++] = vim_strsave(str);
+	    }
 	    else if (is_term_opt)
 	    {
 		name_buf[0] = '<';
@@ -6509,25 +6599,18 @@ ExpandSettings(
 		name_buf[4] = str[3];
 		name_buf[5] = '>';
 		name_buf[6] = NUL;
-		if (vim_regexec(regmatch, name_buf, (colnr_T)0))
-		{
-		    match = TRUE;
-		    str = name_buf;
-		}
-	    }
-	    if (match)
-	    {
-		if (loop == 0)
+
+		if (match_str(name_buf, regmatch, *matches, count, (loop == 0),
+			    fuzzy, fuzzystr, fuzmatch))
 		{
-		    if (is_term_opt)
+		    if (loop == 0)
 			num_term++;
 		    else
-			num_normal++;
+			count++;
 		}
-		else
-		    (*file)[count++] = vim_strsave(str);
 	    }
 	}
+
 	/*
 	 * Check terminal key codes, these are not in the option table
 	 */
@@ -6544,9 +6627,14 @@ ExpandSettings(
 		name_buf[3] = str[1];
 		name_buf[4] = NUL;
 
-		match = FALSE;
-		if (vim_regexec(regmatch, name_buf, (colnr_T)0))
-		    match = TRUE;
+		if (match_str(name_buf, regmatch, *matches, count,
+					(loop == 0), fuzzy, fuzzystr, fuzmatch))
+		{
+		    if (loop == 0)
+			num_term++;
+		    else
+			count++;
+		}
 		else
 		{
 		    name_buf[0] = '<';
@@ -6557,15 +6645,15 @@ ExpandSettings(
 		    name_buf[5] = '>';
 		    name_buf[6] = NUL;
 
-		    if (vim_regexec(regmatch, name_buf, (colnr_T)0))
-			match = TRUE;
-		}
-		if (match)
-		{
-		    if (loop == 0)
-			num_term++;
-		    else
-			(*file)[count++] = vim_strsave(name_buf);
+		    if (match_str(name_buf, regmatch, *matches, count,
+					    (loop == 0), fuzzy, fuzzystr,
+					    fuzmatch))
+		    {
+			if (loop == 0)
+			    num_term++;
+			else
+			    count++;
+		    }
 		}
 	    }
 
@@ -6579,31 +6667,49 @@ ExpandSettings(
 		STRCPY(name_buf + 1, str);
 		STRCAT(name_buf, ">");
 
-		if (vim_regexec(regmatch, name_buf, (colnr_T)0))
+		if (match_str(name_buf, regmatch, *matches, count, (loop == 0),
+			    fuzzy, fuzzystr, fuzmatch))
 		{
 		    if (loop == 0)
 			num_term++;
 		    else
-			(*file)[count++] = vim_strsave(name_buf);
+			count++;
 		}
 	    }
 	}
 	if (loop == 0)
 	{
 	    if (num_normal > 0)
-		*num_file = num_normal;
+		*numMatches = num_normal;
 	    else if (num_term > 0)
-		*num_file = num_term;
+		*numMatches = num_term;
 	    else
 		return OK;
-	    *file = ALLOC_MULT(char_u *, *num_file);
-	    if (*file == NULL)
+	    if (!fuzzy)
 	    {
-		*file = (char_u **)"";
-		return FAIL;
+		*matches = ALLOC_MULT(char_u *, *numMatches);
+		if (*matches == NULL)
+		{
+		    *matches = (char_u **)"";
+		    return FAIL;
+		}
+	    }
+	    else
+	    {
+		fuzmatch = ALLOC_MULT(fuzmatch_str_T, *numMatches);
+		if (fuzmatch == NULL)
+		{
+		    *matches = (char_u **)"";
+		    return FAIL;
+		}
 	    }
 	}
     }
+
+    if (fuzzy &&
+	fuzzymatches_to_strmatches(fuzmatch, matches, count, FALSE) == FAIL)
+	return FAIL;
+
     return OK;
 }
 
diff --git a/src/option.h b/src/option.h
index ebbf94b069..2116fe9951 100644
--- a/src/option.h
+++ b/src/option.h
@@ -358,6 +358,7 @@ typedef enum {
 
 // flags for the 'wildoptions' option
 // each defined char should be unique over all values.
+#define WOP_FUZZY	'z'
 #define WOP_TAGFILE	't'
 #define WOP_PUM		'p'
 
diff --git a/src/optionstr.c b/src/optionstr.c
index c8bef03099..5c3f76dc9e 100644
--- a/src/optionstr.c
+++ b/src/optionstr.c
@@ -57,7 +57,7 @@ static char *(p_tbis_values[]) = {"tiny", "small", "medium", "large", "huge", "g
 static char *(p_ttym_values[]) = {"xterm", "xterm2", "dec", "netterm", "jsbterm", "pterm", "urxvt", "sgr", NULL};
 #endif
 static char *(p_ve_values[]) = {"block", "insert", "all", "onemore", "none", "NONE", NULL};
-static char *(p_wop_values[]) = {"tagfile", "pum", NULL};
+static char *(p_wop_values[]) = {"fuzzy", "tagfile", "pum", NULL};
 #ifdef FEAT_WAK
 static char *(p_wak_values[]) = {"yes", "menu", "no", NULL};
 #endif
diff --git a/src/proto/cmdexpand.pro b/src/proto/cmdexpand.pro
index b64c6bbdc6..5ffab8c545 100644
--- a/src/proto/cmdexpand.pro
+++ b/src/proto/cmdexpand.pro
@@ -1,4 +1,5 @@
 /* cmdexpand.c */
+int cmdline_fuzzy_complete(char_u *fuzzystr);
 int nextwild(expand_T *xp, int type, int options, int escape);
 char_u *ExpandOne(expand_T *xp, char_u *str, char_u *orig, int options, int mode);
 void ExpandInit(expand_T *xp);
diff --git a/src/proto/option.pro b/src/proto/option.pro
index b58e79afef..373a60ca0e 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -63,7 +63,7 @@ void reset_modifiable(void);
 void set_iminsert_global(void);
 void set_imsearch_global(void);
 void set_context_in_set_cmd(expand_T *xp, char_u *arg, int opt_flags);
-int ExpandSettings(expand_T *xp, regmatch_T *regmatch, int *num_file, char_u ***file);
+int ExpandSettings(expand_T *xp, regmatch_T *regmatch, char_u *pat, int *numMatches, char_u ***matches);
 int ExpandOldSetting(int *num_file, char_u ***file);
 int shortmess(int x);
 void vimrc_found(char_u *fname, char_u *envname);
diff --git a/src/proto/search.pro b/src/proto/search.pro
index 27c609e200..bdd9213c75 100644
--- a/src/proto/search.pro
+++ b/src/proto/search.pro
@@ -40,4 +40,7 @@ void f_searchcount(typval_T *argvars, typval_T *rettv);
 int fuzzy_match(char_u *str, char_u *pat_arg, int matchseq, int *outScore, int_u *matches, int maxMatches);
 void f_matchfuzzy(typval_T *argvars, typval_T *rettv);
 void f_matchfuzzypos(typval_T *argvars, typval_T *rettv);
+int fuzzy_match_str(char_u *str, char_u *pat);
+int fuzzymatches_to_strmatches(fuzmatch_str_T *fuzmatch, char_u ***matches, int	count, int funcsort);
+void fuzmatch_str_free(fuzmatch_str_T *fuzmatch, int count);
 /* vim: set ft=c : */
diff --git a/src/search.c b/src/search.c
index dbc766f9f5..00a9fdfc6d 100644
--- a/src/search.c
+++ b/src/search.c
@@ -1166,7 +1166,7 @@ searchit(
     return submatch + 1;
 }
 
-#ifdef FEAT_EVAL
+#if defined(FEAT_EVAL) || defined(FEAT_PROTO)
     void
 set_search_direction(int cdir)
 {
@@ -4107,7 +4107,7 @@ get_spat_last_idx(void)
 }
 #endif
 
-#ifdef FEAT_EVAL
+#if defined(FEAT_EVAL) || defined(FEAT_PROTO)
 /*
  * "searchcount()" function
  */
@@ -4230,6 +4230,7 @@ the_end:
     restore_incsearch_state();
 #endif
 }
+#endif
 
 /*
  * Fuzzy string matching
@@ -4611,6 +4612,7 @@ fuzzy_match(
     return numMatches != 0;
 }
 
+#if defined(FEAT_EVAL) || defined(FEAT_PROTO)
 /*
  * Sort the fuzzy matches in the descending order of the match score.
  * For items with same score, retain the order using the index (stable sort)
@@ -4933,5 +4935,131 @@ f_matchfuzzypos(typval_T *argvars, typval_T *rettv)
 {
     do_fuzzymatch(argvars, rettv, TRUE);
 }
-
 #endif
+
+/*
+ * Same as fuzzy_match_item_compare() except for use with a string match
+ */
+    static int
+fuzzy_match_str_compare(const void *s1, const void *s2)
+{
+    int		v1 = ((fuzmatch_str_T *)s1)->score;
+    int		v2 = ((fuzmatch_str_T *)s2)->score;
+    int		idx1 = ((fuzmatch_str_T *)s1)->idx;
+    int		idx2 = ((fuzmatch_str_T *)s2)->idx;
+
+    return v1 == v2 ? (idx1 - idx2) : v1 > v2 ? -1 : 1;
+}
+
+/*
+ * Sort fuzzy matches by score
+ */
+    static void
+fuzzy_match_str_sort(fuzmatch_str_T *fm, int sz)
+{
+    // Sort the list by the descending order of the match score
+    qsort((void *)fm, (size_t)sz, sizeof(fuzmatch_str_T),
+	    fuzzy_match_str_compare);
+}
+
+/*
+ * Same as fuzzy_match_item_compare() except for use with a function name
+ * string match. <SNR> functions should be sorted to the end.
+ */
+    static int
+fuzzy_match_func_compare(const void *s1, const void *s2)
+{
+    int		v1 = ((fuzmatch_str_T *)s1)->score;
+    int		v2 = ((fuzmatch_str_T *)s2)->score;
+    int		idx1 = ((fuzmatch_str_T *)s1)->idx;
+    int		idx2 = ((fuzmatch_str_T *)s2)->idx;
+    char_u	*str1 = ((fuzmatch_str_T *)s1)->str;
+    char_u	*str2 = ((fuzmatch_str_T *)s2)->str;
+
+    if (*str1 != '<' && *str2 == '<') return -1;
+    if (*str1 == '<' && *str2 != '<') return 1;
+    return v1 == v2 ? (idx1 - idx2) : v1 > v2 ? -1 : 1;
+}
+
+/*
+ * Sort fuzzy matches of function names by score.
+ * <SNR> functions should be sorted to the end.
+ */
+    static void
+fuzzy_match_func_sort(fuzmatch_str_T *fm, int sz)
+{
+    // Sort the list by the descending order of the match score
+    qsort((void *)fm, (size_t)sz, sizeof(fuzmatch_str_T),
+		fuzzy_match_func_compare);
+}
+
+/*
+ * Fuzzy match 'pat' in 'str'. Returns 0 if there is no match. Otherwise,
+ * returns the match score.
+ */
+    int
+fuzzy_match_str(char_u *str, char_u *pat)
+{
+    int		score = 0;
+    int_u	matchpos[256];
+
+    if (str == NULL || pat == NULL)
+	return 0;
+
+    fuzzy_match(str, pat, FALSE, &score, matchpos,
+				sizeof(matchpos) / sizeof(matchpos[0]));
+
+    return score;
+}
+
+/*
+ * Copy a list of fuzzy matches into a string list after sorting the matches by
+ * the fuzzy score. Frees the memory allocated for 'fuzmatch'.
+ * Returns OK on success and FAIL on memory allocation failure.
+ */
+    int
+fuzzymatches_to_strmatches(
+	fuzmatch_str_T	*fuzmatch,
+	char_u		***matches,
+	int		count,
+	int		funcsort)
+{
+    int		i;
+
+    if (count <= 0)
+	return OK;
+
+    *matches = ALLOC_MULT(char_u *, count);
+    if (*matches == NULL)
+    {
+	for (i = 0; i < count; i++)
+	    vim_free(fuzmatch[i].str);
+	vim_free(fuzmatch);
+	return FAIL;
+    }
+
+    // Sort the list by the descending order of the match score
+    if (funcsort)
+	fuzzy_match_func_sort((void *)fuzmatch, (size_t)count);
+    else
+	fuzzy_match_str_sort((void *)fuzmatch, (size_t)count);
+
+    for (i = 0; i < count; i++)
+	(*matches)[i] = fuzmatch[i].str;
+    vim_free(fuzmatch);
+
+    return OK;
+}
+
+/*
+ * Free a list of fuzzy string matches.
+ */
+    void
+fuzmatch_str_free(fuzmatch_str_T *fuzmatch, int count)
+{
+    if (count <= 0 || fuzmatch == NULL)
+	return;
+    while (count--)
+	vim_free(fuzmatch[count].str);
+    vim_free(fuzmatch);
+}
diff --git a/src/structs.h b/src/structs.h
index 1e759f5dfd..1a98004527 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -4516,3 +4516,11 @@ typedef struct {
     int		sw_same_win;	    // VIsual_active was not reset
     int		sw_visual_active;
 } switchwin_T;
+
+// Fuzzy matched string list item. Used for fuzzy match completion. Items are
+// usually sorted by 'score'. The 'idx' member is used for stable-sort.
+typedef struct {
+    int		idx;
+    char_u	*str;
+    int		score;
+} fuzmatch_str_T;
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index abf11fc9dc..e6b16c9def 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -11,6 +11,7 @@ set nomore
 " Clear out t_WS, we don't want to resize the actual terminal.
 let script = [
       \ '" DO NOT EDIT: Generated with gen_opt_test.vim',
+      \ '" Used by test_options.vim.',
       \ '',
       \ 'let save_columns = &columns',
       \ 'let save_lines = &lines',
@@ -152,7 +153,7 @@ let test_values = {
       \ 'virtualedit': [['', 'all', 'all,block'], ['xxx']],
       \ 'whichwrap': [['', 'b,s', 'bs'], ['xxx']],
       \ 'wildmode': [['', 'full', 'list:full', 'full,longest'], ['xxx', 'a4', 'full,full,full,full,full']],
-      \ 'wildoptions': [['', 'tagfile'], ['xxx']],
+      \ 'wildoptions': [['', 'tagfile', 'pum', 'fuzzy'], ['xxx']],
       \ 'winaltkeys': [['menu', 'no'], ['', 'xxx']],
       \
       \ 'luadll': [[], []],
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 337cb42988..1ee0d718e2 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -1574,6 +1574,12 @@ func Test_cmdwin_jump_to_win()
   call assert_equal(1, winnr('$'))
 endfunc
 
+func Test_cmdwin_tabpage()
+  tabedit
+  call assert_fails("silent norm q/g	:I\<Esc>", 'E11:')
+  tabclose!
+endfunc