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>
diff --git a/src/drawline.c b/src/drawline.c
index a6b6317..f0a7a92 100644
--- a/src/drawline.c
+++ b/src/drawline.c
@@ -1877,7 +1877,8 @@
     }
 #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 @@
 #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);
diff --git a/src/insexpand.c b/src/insexpand.c
index 856c06d..9fdc1c0 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -172,6 +172,7 @@
 // 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_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);
@@ -919,21 +922,55 @@
 /*
  * 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".
  */
     static void
@@ -3123,6 +3160,7 @@
     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,
@@ -4342,6 +4380,8 @@
     // 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)
     {
@@ -4349,6 +4389,30 @@
 	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 @@
 	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();
@@ -4367,6 +4438,38 @@
 }
 
 /*
+ * 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().
  * "move_cursor" is used when 'completeopt' includes "preinsert" and when TRUE
@@ -4375,19 +4478,25 @@
     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 @@
     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 @@
 	    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)
 	{
diff --git a/src/proto/insexpand.pro b/src/proto/insexpand.pro
index fe3fead..9dfbd91 100644
--- a/src/proto/insexpand.pro
+++ b/src/proto/insexpand.pro
@@ -61,7 +61,8 @@
 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 : */
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_01.dump b/src/testdir/dumps/Test_pum_with_special_characters_01.dump
new file mode 100644
index 0000000..ae31606
--- /dev/null
+++ b/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
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_02.dump b/src/testdir/dumps/Test_pum_with_special_characters_02.dump
new file mode 100644
index 0000000..6a3dfe9
--- /dev/null
+++ b/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
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_03.dump b/src/testdir/dumps/Test_pum_with_special_characters_03.dump
new file mode 100644
index 0000000..7809629
--- /dev/null
+++ b/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
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_04.dump b/src/testdir/dumps/Test_pum_with_special_characters_04.dump
new file mode 100644
index 0000000..e45b162
--- /dev/null
+++ b/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
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_05.dump b/src/testdir/dumps/Test_pum_with_special_characters_05.dump
new file mode 100644
index 0000000..7cb6656
--- /dev/null
+++ b/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
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_06.dump b/src/testdir/dumps/Test_pum_with_special_characters_06.dump
new file mode 100644
index 0000000..5269700
--- /dev/null
+++ b/src/testdir/dumps/Test_pum_with_special_characters_06.dump
@@ -0,0 +1,12 @@
+|h+0&#ffffff0|e|l@1|o| > |h|e|r|o| @63
+|~+0#4040ff13&| @3| +0#0000001#ffd7ff255|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
+|~| @73
+|~| @73
+|-+2#0000000&@1| |O|m|n|i| |c|o|m|p|l|e|t|i|o|n| |(|^|O|^|N|^|P|)| |B+0#e000002&|a|c|k| |a|t| |o|r|i|g|i|n|a|l| +0#0000000&@30
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_07.dump b/src/testdir/dumps/Test_pum_with_special_characters_07.dump
new file mode 100644
index 0000000..adafb9f
--- /dev/null
+++ b/src/testdir/dumps/Test_pum_with_special_characters_07.dump
@@ -0,0 +1,12 @@
+|f+0#ff404010#ffffff0|u|n|c| |(|)| +0#0000000&@67
+| +0#ff404010&@7| +0#0000000&@66
+|e+0#ff404010&|n|d> +0#0000000&@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
diff --git a/src/testdir/dumps/Test_pum_with_special_characters_08.dump b/src/testdir/dumps/Test_pum_with_special_characters_08.dump
new file mode 100644
index 0000000..bf558c1
--- /dev/null
+++ b/src/testdir/dumps/Test_pum_with_special_characters_08.dump
@@ -0,0 +1,12 @@
+|h+0&#ffffff0|e|l@1|o| |f+0#ff404010&|u|n|c| |(|)| +0#0000000&@61
+| +0#ff404010&@7| +0#0000000&@66
+|e+0#ff404010&|n|d> |h+0#0000000&|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
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index fb5d07b..7c8faa9 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -1894,4 +1894,59 @@
   bw!
 endfunc
 
+func Test_pum_complete_with_special_characters()
+  CheckScreendump
+
+  let lines =<< trim END
+    func Omni_test(findstart, base)
+      if a:findstart
+        return col(".")
+      endif
+      return [#{word: "func ()\n\t\nend", abbr: "function ()",}, #{word: "foobar"}, #{word: "你好\n\t\n我好"}]
+    endfunc
+    set omnifunc=Omni_test
+  END
+
+  call writefile(lines, 'Xpreviewscript', 'D')
+  let buf = RunVimInTerminal('-S Xpreviewscript', #{rows: 12})
+  call term_sendkeys(buf, "S\<C-X>\<C-O>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_01', {})
+
+  call term_sendkeys(buf, "\<C-N>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_02', {})
+  call term_sendkeys(buf, "\<C-E>\<Esc>")
+
+  call term_sendkeys(buf, "Shello  hero\<ESC>hhhhha\<C-X>\<C-O>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_03', {})
+
+  call term_sendkeys(buf, "\<C-N>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_04', {})
+
+  call term_sendkeys(buf, "\<C-N>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_05', {})
+
+  call term_sendkeys(buf, "\<C-N>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_06', {})
+  call term_sendkeys(buf, "\<C-E>\<Esc>")
+
+  call term_sendkeys(buf, ":hi ComplMatchIns ctermfg=red\<CR>")
+  call TermWait(buf, 50)
+  call term_sendkeys(buf, "S\<C-X>\<C-O>")
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_07', {})
+  call term_sendkeys(buf, "\<C-E>\<Esc>")
+
+  call term_sendkeys(buf, "Shello  hero\<ESC>hhhhha\<C-X>\<C-O>")
+  call TermWait(buf, 50)
+  call VerifyScreenDump(buf, 'Test_pum_with_special_characters_08', {})
+  call term_sendkeys(buf, "\<C-E>\<Esc>")
+
+  call StopVimInTerminal(buf)
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 20eafbb..b8f783e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1086,
+/**/
     1085,
 /**/
     1084,