patch 8.1.2314: vi' sometimes does not select anything

Problem:    vi' sometimes does not select anything.
Solution:   Recognize an empty selection. (Christian Brabandt, closes #5183)

Author: brammool

src/search.c

@@ -4434,9 +4434,10 @@ current_quote(
 	    return FALSE;
 
 	vis_bef_curs = LT_POS(VIsual, curwin->w_cursor);
+	vis_empty = EQUAL_POS(VIsual, curwin->w_cursor);
 	if (*p_sel == 'e')
 	{
-	    if (!vis_bef_curs)
+	    if (!vis_bef_curs && !vis_empty)
 	    {
 		// VIsual needs to be the start of Visual selection.
 		pos_T t = curwin->w_cursor;
@@ -4447,8 +4448,8 @@ current_quote(
 		restore_vis_bef = TRUE;
 	    }
 	    dec_cursor();
+	    vis_empty = EQUAL_POS(VIsual, curwin->w_cursor);
 	}
-	vis_empty = EQUAL_POS(VIsual, curwin->w_cursor);
     }
 
     if (!vis_empty)

src/testdir/test_textobjects.vim

@@ -47,6 +47,9 @@ func Test_quote_selection_selection_exclusive()
   set selection=exclusive
   exe "norm! fdvhi'y"
   call assert_equal('bcde', @")
+  let @"='dummy'
+  exe "norm! $gevi'y"
+  call assert_equal('bcde', @")
   set selection&vim
   bw!
 endfunc

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2314,
 /**/
     2313,
 /**/