patch 9.1.1086: completion doesn't work with multi lines

Problem:  completion doesn't work with multi lines
          (Ɓukasz 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);