patch 8.1.1123: no way to avoid filtering for autocomplete function

Problem:    No way to avoid filtering for autocomplete function, causing
            flickering of the popup menu.
Solution:   Add the "equal" field to complete items. (closes #3887)

runtime/doc/insert.txt

@@ -1105,6 +1105,9 @@ items:
 	icase		when non-zero case is to be ignored when comparing
 			items to be equal; when omitted zero is used, thus
 			items that only differ in case are added
+	equal		when non-zero, always treat this item to be equal when
+			comparing. Which means, "equal=1" disables filtering
+			of this item.
 	dup		when non-zero this match will be added even when an
 			item with the same word is already present.
 	empty		when non-zero this match will be added even when it is
@@ -1112,10 +1115,10 @@ items:
 	user_data 	custom data which is associated with the item and
 			available in |v:completed_item|
 
-All of these except "icase", "dup" and "empty" must be a string.  If an item
+All of these except "icase", "equal", "dup" and "empty" must be a string.  If
-does not meet these requirements then an error message is given and further
+an item does not meet these requirements then an error message is given and
-items in the list are not used.  You can mix string and Dictionary items in
+further items in the list are not used.  You can mix string and Dictionary
-the returned list.
+items in the returned list.
 
 The "menu" item is used in the popup menu and may be truncated, thus it should
 be relatively short.  The "info" item can be longer, it will  be displayed in

src/insexpand.c

@@ -101,16 +101,18 @@ struct compl_S
 {
     compl_T	*cp_next;
     compl_T	*cp_prev;
-    char_u	*cp_str;	/* matched text */
+    char_u	*cp_str;	// matched text
-    char	cp_icase;	/* TRUE or FALSE: ignore case */
+    char	cp_icase;	// TRUE or FALSE: ignore case
-    char_u	*(cp_text[CPT_COUNT]);	/* text for the menu */
+    char	cp_equal;       // TRUE or FALSE: ins_compl_equal always ok
-    char_u	*cp_fname;	/* file containing the match, allocated when
+    char_u	*(cp_text[CPT_COUNT]);	// text for the menu
-				 * cp_flags has FREE_FNAME */
+    char_u	*cp_fname;	// file containing the match, allocated when
-    int		cp_flags;	/* ORIGINAL_TEXT, CONT_S_IPOS or FREE_FNAME */
+				// cp_flags has FREE_FNAME
-    int		cp_number;	/* sequence number */
+    int		cp_flags;	// ORIGINAL_TEXT, CONT_S_IPOS or FREE_FNAME
+    int		cp_number;	// sequence number
 };
 
-# define ORIGINAL_TEXT	(1)   /* the original text when the expansion begun */
+// flags for ins_compl_add()
+# define ORIGINAL_TEXT	(1)   // the original text when the expansion begun
 # define FREE_FNAME	(2)
 
 static char e_hitend[] = N_("Hit end of paragraph");
@@ -183,7 +185,7 @@ static expand_T	  compl_xp;
 static int	  compl_opt_refresh_always = FALSE;
 static int	  compl_opt_suppress_empty = FALSE;
 
-static int ins_compl_add(char_u *str, int len, int icase, char_u *fname, char_u **cptext, int cdir, int flags, int adup);
+static int ins_compl_add(char_u *str, int len, int icase, char_u *fname, char_u **cptext, int cdir, int flags, int adup, int equal);
 static void ins_compl_longest_match(compl_T *match);
 static void ins_compl_del_pum(void);
 static void ins_compl_files(int count, char_u **files, int thesaurus, int flags, regmatch_T *regmatch, char_u *buf, int *dir);
@@ -413,13 +415,14 @@ ins_compl_accept_char(int c)
  */
     int
 ins_compl_add_infercase(
-    char_u	*str,
+    char_u	*str_arg,
     int		len,
     int		icase,
     char_u	*fname,
     int		dir,
     int		flags)
 {
+    char_u	*str = str_arg;
     char_u	*p;
     int		i, c;
     int		actual_len;		// Take multi-byte characters
@@ -550,10 +553,11 @@ ins_compl_add_infercase(
 	    vim_free(wca);
 	}
 
-	return ins_compl_add(IObuff, len, icase, fname, NULL, dir,
+	str = IObuff;
-								flags, FALSE);
     }
-    return ins_compl_add(str, len, icase, fname, NULL, dir, flags, FALSE);
+
+    return ins_compl_add(str, len, icase, fname, NULL, dir,
+							  flags, FALSE, FALSE);
 }
 
 /*
@@ -571,7 +575,8 @@ ins_compl_add(
     char_u	**cptext,   // extra text for popup menu or NULL
     int		cdir,
     int		flags,
-    int		adup)	    // accept duplicate match
+    int		adup,	    // accept duplicate match
+    int		equal)      // match is always accepted by ins_compl_equal
 {
     compl_T	*match;
     int		dir = (cdir == 0 ? compl_direction : cdir);
@@ -613,6 +618,7 @@ ins_compl_add(
 	return FAIL;
     }
     match->cp_icase = icase;
+    match->cp_equal = equal;
 
     // match-fname is:
     // - compl_curr_match->cp_fname if it is a string equal to fname.
@@ -676,6 +682,8 @@ ins_compl_add(
     static int
 ins_compl_equal(compl_T *match, char_u *str, int len)
 {
+    if (match->cp_equal)
+	return TRUE;
     if (match->cp_icase)
 	return STRNICMP(match->cp_str, str, (size_t)len) == 0;
     return STRNCMP(match->cp_str, str, (size_t)len) == 0;
@@ -776,7 +784,7 @@ ins_compl_add_matches(
 
     for (i = 0; i < num_matches && add_r != FAIL; i++)
 	if ((add_r = ins_compl_add(matches[i], -1, icase,
-					    NULL, NULL, dir, 0, FALSE)) == OK)
+				      NULL, NULL, dir, 0, FALSE, FALSE)) == OK)
 	    // if dir was BACKWARD then honor it just once
 	    dir = FORWARD;
     FreeWild(num_matches, matches);
@@ -868,7 +876,7 @@ set_completion(colnr_T startcol, list_T *list)
     // compl_pattern doesn't need to be set
     compl_orig_text = vim_strnsave(ml_get_curline() + compl_col, compl_length);
     if (compl_orig_text == NULL || ins_compl_add(compl_orig_text,
-			-1, p_ic, NULL, NULL, 0, ORIGINAL_TEXT, FALSE) != OK)
+		   -1, p_ic, NULL, NULL, 0, ORIGINAL_TEXT, FALSE, FALSE) != OK)
 	return;
 
     ctrl_x_mode = CTRL_X_EVAL;
@@ -2365,6 +2373,7 @@ ins_compl_add_tv(typval_T *tv, int dir)
     int		icase = FALSE;
     int		adup = FALSE;
     int		aempty = FALSE;
+    int		aequal = FALSE;
     char_u	*(cptext[CPT_COUNT]);
 
     if (tv->v_type == VAR_DICT && tv->vval.v_dict != NULL)
@@ -2386,6 +2395,8 @@ ins_compl_add_tv(typval_T *tv, int dir)
 	    adup = dict_get_number(tv->vval.v_dict, (char_u *)"dup");
 	if (dict_get_string(tv->vval.v_dict, (char_u *)"empty", FALSE) != NULL)
 	    aempty = dict_get_number(tv->vval.v_dict, (char_u *)"empty");
+	if (dict_get_string(tv->vval.v_dict, (char_u *)"equal", FALSE) != NULL)
+	    aequal = dict_get_number(tv->vval.v_dict, (char_u *)"equal");
     }
     else
     {
@@ -2394,7 +2405,7 @@ ins_compl_add_tv(typval_T *tv, int dir)
     }
     if (word == NULL || (!aempty && *word == NUL))
 	return FAIL;
-    return ins_compl_add(word, -1, icase, NULL, cptext, dir, 0, adup);
+    return ins_compl_add(word, -1, icase, NULL, cptext, dir, 0, adup, aequal);
 }
 #endif
 
@@ -3694,7 +3705,7 @@ ins_complete(int c, int enable_pum)
 	vim_free(compl_orig_text);
 	compl_orig_text = vim_strnsave(line + compl_col, compl_length);
 	if (compl_orig_text == NULL || ins_compl_add(compl_orig_text,
-			-1, p_ic, NULL, NULL, 0, ORIGINAL_TEXT, FALSE) != OK)
+		   -1, p_ic, NULL, NULL, 0, ORIGINAL_TEXT, FALSE, FALSE) != OK)
 	{
 	    VIM_CLEAR(compl_pattern);
 	    VIM_CLEAR(compl_orig_text);

src/testdir/test_popup.vim

@@ -276,6 +276,38 @@ func Test_noinsert_complete()
   iunmap <F5>
 endfunc
 
+func Test_complete_no_filter()
+  func! s:complTest1() abort
+    call complete(1, [{'word': 'foobar'}])
+    return ''
+  endfunc
+  func! s:complTest2() abort
+    call complete(1, [{'word': 'foobar', 'equal': 1}])
+    return ''
+  endfunc
+
+  let completeopt = &completeopt
+
+  " without equal=1
+  new
+  set completeopt=menuone,noinsert,menu
+  inoremap <F5>  <C-R>=s:complTest1()<CR>
+  call feedkeys("i\<F5>z\<CR>\<CR>\<ESC>.", 'tx')
+  call assert_equal('z', getline(1))
+  bwipe!
+
+  " with equal=1
+  new
+  set completeopt=menuone,noinsert,menu
+  inoremap <F5>  <C-R>=s:complTest2()<CR>
+  call feedkeys("i\<F5>z\<CR>\<CR>\<ESC>.", 'tx')
+  call assert_equal('foobar', getline(1))
+  bwipe!
+
+  let &completeopt = completeopt
+  iunmap <F5>
+endfunc
+
 func Test_compl_vim_cmds_after_register_expr()
   func! s:test_func()
     return 'autocmd '

src/version.c

@@ -771,6 +771,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1123,
 /**/
     1122,
 /**/