patch 8.1.0018: using "gn" may select wrong text when wrapping

Problem:    Using "gn" may select wrong text when wrapping.
Solution:   Avoid wrapping when searching forward. (Christian Brabandt)

src/search.c

@@ -4665,6 +4665,7 @@ current_search(
 {
     pos_T	start_pos;	/* position before the pattern */
     pos_T	orig_pos;	/* position of the cursor at beginning */
+    pos_T	first_match;	/* position of first match */
     pos_T	pos;		/* position after the pattern */
     int		i;
     int		dir;
@@ -4758,6 +4759,8 @@ current_search(
 				ml_get(curwin->w_buffer->b_ml.ml_line_count));
 	    }
 	}
+	if (i == 0)
+	    first_match = pos;
 	p_ws = old_p_ws;
     }
 
@@ -4774,9 +4777,25 @@ current_search(
     /* move to match, except for zero-width matches, in which case, we are
      * already on the next match */
     if (!one_char)
+    {
+	p_ws = FALSE;
+	for (i = 0; i < 2; i++)
+	{
 	    result = searchit(curwin, curbuf, &pos, direction,
 		    spats[last_idx].pat, 0L, flags | SEARCH_KEEP, RE_SEARCH, 0,
 								   NULL, NULL);
+	    /* Search successfull, break out from the loop */
+	    if (result)
+		break;
+	    /* search failed, try again from the last search position match */
+	    pos = first_match;
+	}
+    }
+
+    p_ws = old_p_ws;
+    /* not found */
+    if (!result)
+	return FAIL;
 
     if (!VIsual_active)
 	VIsual = start_pos;

src/testdir/test_gn.vim

@@ -119,6 +119,15 @@ func Test_gn_command()
   call assert_equal(['foo', 'bar', '', 'baz'], getline(1,'$'))
   sil! %d_
 
+  " search using the \zs atom
+  call setline(1, [' nnoremap', '' , 'nnoremap'])
+  set wrapscan&vim
+  let @/ = '\_s\zsnnoremap'
+  $
+  norm! cgnmatch
+  call assert_equal([' nnoremap', '', 'match'], getline(1,'$'))
+  sil! %d_
+
   set wrapscan&vim
 endfu
 

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    18,
 /**/
     17,
 /**/