patch 9.1.1086: completion doesn't work with multi lines

Problem:  completion doesn't work with multi lines
          (Łukasz Jan Niemier)
Solution: handle linebreaks in completion code as expected
          (glepnir)

fixes: #2505
closes: #15373

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Author: glepnir

runtime/doc/version9.txt

@@ -41638,6 +41638,7 @@ Changed~
 - new digraph "APPROACHES THE LIMIT" using ".="
 - Add the optional {opts} |Dict| argument to |getchar()| to control: cursor
   behaviour, return type and whether or not to simplify the returned key
+- handle multi-line completion as expected
 
 							*added-9.2*
 Added ~

runtime/filetype.vim

@@ -1,7 +1,7 @@
 " Vim support file to detect file types
 "
 " Maintainer:	The Vim Project <https://github.com/vim/vim>
-" Last Change:	2025 Jan 21
+" Last Change:	2025 Feb 08
 " Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 " Listen very carefully, I will say this only once

src/drawline.c

@@ -1877,7 +1877,8 @@ win_line(
     }
 #endif
 
-    if ((State & MODE_INSERT) && in_curline && ins_compl_win_active(wp))
+    if ((State & MODE_INSERT) && ins_compl_win_active(wp)
+			    && (in_curline || ins_compl_lnum_in_range(lnum)))
 	area_highlighting = TRUE;
 
 #ifdef FEAT_SYN_HL
@@ -2423,11 +2424,11 @@ win_line(
 #endif
 
 		// Check if ComplMatchIns highlight is needed.
-		if ((State & MODE_INSERT) && in_curline
-						&& ins_compl_win_active(wp))
+		if ((State & MODE_INSERT) && ins_compl_win_active(wp)
+			    && (in_curline || ins_compl_lnum_in_range(lnum)))
 		{
 		    int ins_match_attr =
-			ins_compl_col_range_attr((int)(ptr - line));
+			ins_compl_col_range_attr(lnum, (int)(ptr - line));
 		    if (ins_match_attr > 0)
 			search_attr =
 			    hl_combine_attr(search_attr, ins_match_attr);

src/insexpand.c

@@ -172,6 +172,7 @@ static pos_T	  compl_startpos;
 // Length in bytes of the text being completed (this is deleted to be replaced
 // by the match.)
 static int	  compl_length = 0;
+static linenr_T	  compl_lnum = 0;           // lnum where the completion start
 static colnr_T	  compl_col = 0;	    // column where the text starts
 					    // that is being completed
 static colnr_T	  compl_ins_end_col = 0;
@@ -226,6 +227,8 @@ static int  ins_compl_pum_key(int c);
 static int  ins_compl_key2count(int c);
 static void show_pum(int prev_w_wrow, int prev_w_leftcol);
 static unsigned  quote_meta(char_u *dest, char_u *str, int len);
+static int ins_compl_has_multiple(void);
+static void ins_compl_expand_multiple(char_u *str);
 
 #ifdef FEAT_SPELL
 static void spell_back_to_badword(void);
@@ -919,20 +922,54 @@ ins_compl_insert_bytes(char_u *p, int len)
 /*
  * Checks if the column is within the currently inserted completion text
  * column range. If it is, it returns a special highlight attribute.
- * -1 mean normal item.
+ * -1 means normal item.
  */
     int
-ins_compl_col_range_attr(int col)
+ins_compl_col_range_attr(linenr_T lnum, int col)
 {
-    if ((get_cot_flags() & COT_FUZZY))
+    int	    start_col;
+    int	    attr;
+
+    if ((get_cot_flags() & COT_FUZZY)
+	    || (attr = syn_name2attr((char_u *)"ComplMatchIns")) == 0)
 	return -1;
 
-    if (col >= (compl_col + (int)ins_compl_leader_len()) && col < compl_ins_end_col)
-	return syn_name2attr((char_u *)"ComplMatchIns");
+    start_col = compl_col + (int)ins_compl_leader_len();
+    if (!ins_compl_has_multiple())
+	return (col >= start_col && col < compl_ins_end_col) ? attr : -1;
+
+    // Multiple lines
+    if ((lnum == compl_lnum && col >= start_col && col < MAXCOL) ||
+	(lnum > compl_lnum && lnum < curwin->w_cursor.lnum) ||
+	(lnum == curwin->w_cursor.lnum && col <= compl_ins_end_col))
+	return attr;
 
     return -1;
 }
 
+/*
+ * Returns TRUE if the current completion string contains newline characters,
+ * indicating it's a multi-line completion.
+ */
+    static int
+ins_compl_has_multiple(void)
+{
+    return vim_strchr(compl_shown_match->cp_str.string, '\n') != NULL;
+}
+
+/*
+ * Returns TRUE if the given line number falls within the range of a multi-line
+ * completion, i.e. between the starting line (compl_lnum) and current cursor
+ * line. Always returns FALSE for single-line completions.
+ */
+    int
+ins_compl_lnum_in_range(linenr_T lnum)
+{
+    if (!ins_compl_has_multiple())
+	return FALSE;
+    return lnum >= compl_lnum && lnum <= curwin->w_cursor.lnum;
+}
+
 /*
  * Reduce the longest common string for match "match".
  */
@@ -3123,6 +3160,7 @@ set_completion(colnr_T startcol, list_T *list)
     if (startcol > curwin->w_cursor.col)
 	startcol = curwin->w_cursor.col;
     compl_col = startcol;
+    compl_lnum = curwin->w_cursor.lnum;
     compl_length = (int)curwin->w_cursor.col - (int)startcol;
     // compl_pattern doesn't need to be set
     compl_orig_text.string = vim_strnsave(ml_get_curline() + compl_col,
@@ -4342,13 +4380,39 @@ ins_compl_delete(void)
     // In insert mode: Delete the typed part.
     // In replace mode: Put the old characters back, if any.
     int col = compl_col + (compl_status_adding() ? compl_length : 0);
+    char_u  *remaining = NULL;
+    int	    orig_col;
     int	has_preinsert = ins_compl_preinsert_effect();
     if (has_preinsert)
     {
 	col += ins_compl_leader_len();
 	curwin->w_cursor.col = compl_ins_end_col;
     }
 
+    if (curwin->w_cursor.lnum > compl_lnum)
+    {
+	if (curwin->w_cursor.col < ml_get_curline_len())
+	{
+	    char_u *line = ml_get_curline();
+	    remaining = vim_strnsave(line + curwin->w_cursor.col,
+				(size_t)STRLEN(line + curwin->w_cursor.col));
+	    if (remaining == NULL)
+		return;
+	}
+	while (curwin->w_cursor.lnum > compl_lnum)
+	{
+	    if (ml_delete(curwin->w_cursor.lnum) == FAIL)
+	    {
+		if (remaining)
+		    VIM_CLEAR(remaining);
+		return;
+	    }
+	    curwin->w_cursor.lnum--;
+	}
+	// move cursor to end of line
+	curwin->w_cursor.col = ml_get_curline_len();
+    }
+
     if ((int)curwin->w_cursor.col > col)
     {
 	if (stop_arrow() == FAIL)
@@ -4357,6 +4421,13 @@ ins_compl_delete(void)
 	compl_ins_end_col = curwin->w_cursor.col;
     }
 
+    if (remaining != NULL)
+    {
+	orig_col = curwin->w_cursor.col;
+	ins_str(remaining);
+	curwin->w_cursor.col = orig_col;
+	vim_free(remaining);
+    }
     // TODO: is this sufficient for redrawing?  Redrawing everything causes
     // flicker, thus we can't do that.
     changed_cline_bef_curs();
@@ -4366,6 +4437,38 @@ ins_compl_delete(void)
 #endif
 }
 
+/*
+ * Insert a completion string that contains newlines.
+ * The string is split and inserted line by line.
+ */
+    static void
+ins_compl_expand_multiple(char_u *str)
+{
+    char_u	*start = str;
+    char_u	*curr = str;
+
+    while (*curr != NUL)
+    {
+	if (*curr == '\n')
+	{
+	    // Insert the text chunk before newline
+	    if (curr > start)
+		ins_char_bytes(start, (int)(curr - start));
+
+	    // Handle newline
+	    open_line(FORWARD, OPENLINE_KEEPTRAIL, FALSE, NULL);
+	    start = curr + 1;
+	}
+	curr++;
+    }
+
+    // Handle remaining text after last newline (if any)
+    if (curr > start)
+	ins_char_bytes(start, (int)(curr - start));
+
+    compl_ins_end_col = curwin->w_cursor.col;
+}
+
 /*
  * Insert the new text being completed.
  * "in_compl_func" is TRUE when called from complete_check().
@@ -4375,19 +4478,25 @@ ins_compl_delete(void)
     void
 ins_compl_insert(int in_compl_func, int move_cursor)
 {
-    int	    compl_len = get_compl_len();
-    int	    preinsert = ins_compl_has_preinsert();
-    char_u  *cp_str = compl_shown_match->cp_str.string;
-    size_t  cp_str_len = compl_shown_match->cp_str.length;
-    size_t  leader_len = ins_compl_leader_len();
+    int		compl_len = get_compl_len();
+    int		preinsert = ins_compl_has_preinsert();
+    char_u	*cp_str = compl_shown_match->cp_str.string;
+    size_t	cp_str_len = compl_shown_match->cp_str.length;
+    size_t	leader_len = ins_compl_leader_len();
+    char_u	*has_multiple = vim_strchr(cp_str, '\n');
 
     // Make sure we don't go over the end of the string, this can happen with
     // illegal bytes.
     if (compl_len < (int)cp_str_len)
     {
-	ins_compl_insert_bytes(cp_str + compl_len, -1);
-	if (preinsert && move_cursor)
-	    curwin->w_cursor.col -= (colnr_T)(cp_str_len - leader_len);
+	if (has_multiple)
+	    ins_compl_expand_multiple(cp_str + compl_len);
+	else
+	{
+	    ins_compl_insert_bytes(cp_str + compl_len, -1);
+	    if (preinsert && move_cursor)
+		curwin->w_cursor.col -= (colnr_T)(cp_str_len - leader_len);
+	}
     }
     if (match_at_original_text(compl_shown_match) || preinsert)
 	compl_used_match = FALSE;
@@ -5373,6 +5482,7 @@ ins_compl_start(void)
     line = ml_get(curwin->w_cursor.lnum);
     curs_col = curwin->w_cursor.col;
     compl_pending = 0;
+    compl_lnum = curwin->w_cursor.lnum;
 
     if ((compl_cont_status & CONT_INTRPT) == CONT_INTRPT
 	    && compl_cont_mode == ctrl_x_mode)
@@ -5423,6 +5533,7 @@ ins_compl_start(void)
 	    curbuf->b_p_com = old;
 	    compl_length = 0;
 	    compl_col = curwin->w_cursor.col;
+	    compl_lnum = curwin->w_cursor.lnum;
 	}
 	else if (ctrl_x_mode_normal() && in_fuzzy)
 	{

src/proto/insexpand.pro

@@ -61,7 +61,8 @@ void ins_compl_delete(void);
 void ins_compl_insert(int in_compl_func, int move_cursor);
 void ins_compl_check_keys(int frequency, int in_compl_func);
 int ins_complete(int c, int enable_pum);
-int ins_compl_col_range_attr(int col);
+int ins_compl_col_range_attr(linenr_T lnum, int col);
 void free_insexpand_stuff(void);
 int ins_compl_preinsert_effect(void);
+int ins_compl_lnum_in_range(linenr_T lnum);
 /* vim: set ft=c : */

src/testdir/dumps/Test_pum_with_special_characters_01.dump

@@ -0,0 +1,12 @@
+|f+0&#ffffff0|u|n|c| |(|)| @67
+@75
+|e|n|d> @71
+|f+0#0000001#e0e0e08|u|n|c|t|i|o|n| |(|)| @3| +0#4040ff13#ffffff0@59
+|f+0#0000001#ffd7ff255|o@1|b|a|r| @8| +0#4040ff13#ffffff0@59
+|你*0#0000001#ffd7ff255|好|^+&|@| @1|^|@|我*&|好| +&| +0#4040ff13#ffffff0@59
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |O|m|n|i| |c|o|m|p|l|e|t|i|o|n| |(|^|O|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |1| |o|f| |3| +0#0000000&@34

src/testdir/dumps/Test_pum_with_special_characters_02.dump

@@ -0,0 +1,12 @@
+|f+0&#ffffff0|o@1|b|a|r> @68
+|f+0#0000001#ffd7ff255|u|n|c|t|i|o|n| |(|)| @3| +0#4040ff13#ffffff0@59
+|f+0#0000001#e0e0e08|o@1|b|a|r| @8| +0#4040ff13#ffffff0@59
+|你*0#0000001#ffd7ff255|好|^+&|@| @1|^|@|我*&|好| +&| +0#4040ff13#ffffff0@59
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |O|m|n|i| |c|o|m|p|l|e|t|i|o|n| |(|^|O|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |2| |o|f| |3| +0#0000000&@34

src/testdir/dumps/Test_pum_with_special_characters_03.dump

@@ -0,0 +1,12 @@
+|h+0&#ffffff0|e|l@1|o| |f|u|n|c| |(|)| @61
+@75
+|e|n|d> |h|e|r|o| @66
+|~+0#4040ff13&| @3| +0#0000001#e0e0e08|f|u|n|c|t|i|o|n| |(|)| @3| +0#4040ff13#ffffff0@53
+|~| @3| +0#0000001#ffd7ff255|f|o@1|b|a|r| @8| +0#4040ff13#ffffff0@53
+|~| @3| +0#0000001#ffd7ff255|你*&|好|^+&|@| @1|^|@|我*&|好| +&| +0#4040ff13#ffffff0@53
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |O|m|n|i| |c|o|m|p|l|e|t|i|o|n| |(|^|O|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |1| |o|f| |3| +0#0000000&@34

src/testdir/dumps/Test_pum_with_special_characters_04.dump

@@ -0,0 +1,12 @@
+|h+0&#ffffff0|e|l@1|o| |f|o@1|b|a|r> |h|e|r|o| @57
+|~+0#4040ff13&| @3| +0#0000001#ffd7ff255|f|u|n|c|t|i|o|n| |(|)| @3| +0#4040ff13#ffffff0@53
+|~| @3| +0#0000001#e0e0e08|f|o@1|b|a|r| @8| +0#4040ff13#ffffff0@53
+|~| @3| +0#0000001#ffd7ff255|你*&|好|^+&|@| @1|^|@|我*&|好| +&| +0#4040ff13#ffffff0@53
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |O|m|n|i| |c|o|m|p|l|e|t|i|o|n| |(|^|O|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |2| |o|f| |3| +0#0000000&@34

src/testdir/dumps/Test_pum_with_special_characters_05.dump

@@ -0,0 +1,12 @@
+|h+0&#ffffff0|e|l@1|o| |你*&|好| +&@64
+@75
+|我*&|好> +&|h|e|r|o| @65
+|~+0#4040ff13&| @1| +0#0000001#ffd7ff255|f|u|n|c|t|i|o|n| |(|)| @3| +0#4040ff13#ffffff0@55
+|~| @1| +0#0000001#ffd7ff255|f|o@1|b|a|r| @8| +0#4040ff13#ffffff0@55
+|~| @1| +0#0000001#e0e0e08|你*&|好|^+&|@| @1|^|@|我*&|好| +&| +0#4040ff13#ffffff0@55
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|-+2#0000000&@1| |O|m|n|i| |c|o|m|p|l|e|t|i|o|n| |(|^|O|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |3| |o|f| |3| +0#0000000&@34