patch 8.2.4917: fuzzy expansion of option names is not right

Problem:    Fuzzy expansion of option names is not right.
Solution:   Pass the fuzzy flag down the call chain. (Christian Brabandt,
            closes #10380, closes #10318)

Author: chrisbra

src/cmdexpand.c

@@ -2787,7 +2787,7 @@ ExpandFromContext(
 
     if (xp->xp_context == EXPAND_SETTINGS
 	    || xp->xp_context == EXPAND_BOOL_SETTINGS)
-	ret = ExpandSettings(xp, &regmatch, pat, numMatches, matches);
+	ret = ExpandSettings(xp, &regmatch, pat, numMatches, matches, fuzzy);
     else if (xp->xp_context == EXPAND_MAPPINGS)
 	ret = ExpandMappings(pat, &regmatch, numMatches, matches);
 # if defined(FEAT_EVAL)

src/option.c

@@ -6511,7 +6511,8 @@ ExpandSettings(
     regmatch_T	*regmatch,
     char_u	*fuzzystr,
     int		*numMatches,
-    char_u	***matches)
+    char_u	***matches,
+    int         can_fuzzy)
 {
     int		num_normal = 0;	    // Nr of matching non-term-code settings
     int		num_term = 0;	    // Nr of matching terminal code settings
@@ -6527,7 +6528,7 @@ ExpandSettings(
     int		fuzzy;
     fuzmatch_str_T  *fuzmatch = NULL;
 
-    fuzzy = cmdline_fuzzy_complete(fuzzystr);
+    fuzzy = can_fuzzy && cmdline_fuzzy_complete(fuzzystr);
 
     // do this loop twice:
     // loop == 0: count the number of matching options

src/proto/option.pro

@@ -64,7 +64,7 @@ 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, char_u *fuzzystr, int *numMatches, char_u ***matches);
+int ExpandSettings(expand_T *xp, regmatch_T *regmatch, char_u *fuzzystr, int *numMatches, char_u ***matches, int do_fuzzy);
 int ExpandOldSetting(int *num_file, char_u ***file);
 int shortmess(int x);
 void vimrc_found(char_u *fname, char_u *envname);

src/testdir/test_options.vim

@@ -1257,4 +1257,26 @@ func Test_opt_cdhome()
   set cdhome&
 endfunc
 
+func Test_set_completion_2()
+  CheckOption termguicolors
+
+  " Test default option completion
+  set wildoptions=
+  call feedkeys(":set termg\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set termguicolors', @:)
+
+  call feedkeys(":set notermg\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set notermguicolors', @:)
+
+  " Test fuzzy option completion
+  set wildoptions=fuzzy
+  call feedkeys(":set termg\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set termguicolors termencoding', @:)
+
+  call feedkeys(":set notermg\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set notermguicolors', @:)
+
+  set wildoptions=
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4917,
 /**/
     4916,
 /**/