patch 8.1.1664: GUI resize may cause changing Rows at a bad time

Problem:    GUI resize may cause changing Rows at a bad time. (Dominique
            Pelle)
Solution:   Postpone resizing while updating the screen.

src/term.c

@@ -3425,11 +3425,15 @@ set_shellsize(int width, int height, int mustset)
 
     if (State == HITRETURN || State == SETWSIZE)
     {
-	/* postpone the resizing */
+	// postpone the resizing
 	State = SETWSIZE;
 	return;
     }
 
+    if (updating_screen)
+	// resizing while in update_screen() may cause a crash
+	return;
+
     /* curwin->w_buffer can be NULL when we are closing a window and the
      * buffer has already been closed and removing a scrollbar causes a resize
      * event. Don't resize then, it will happen after entering another buffer.

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1664,
 /**/
     1663,
 /**/