Problem: crash with WinNewPre autocommand

Problem:  crash with WinNewPre autocommand, because window
          structures are not yet safe to use
Solution: Don't trigger WinNewPre on :tabnew

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/window.c

@@ -4607,6 +4607,11 @@ free_tabpage(tabpage_T *tp)
  * It will edit the current buffer, like after ":split".
  * When "after" is 0 put it just after the current Tab page.
  * Otherwise put it just before tab page "after".
+ *
+ * Does not trigger WinNewPre, since the window structures
+ * are not completly setup yet and could cause dereferencing
+ * NULL pointers
+ *
  * Return FAIL or OK.
  */
     int
@@ -4640,8 +4645,6 @@ win_new_tabpage(int after)
     newtp->tp_localdir = (tp->tp_localdir == NULL)
 				    ? NULL : vim_strsave(tp->tp_localdir);
 
-    trigger_winnewpre();
-
     // Create a new empty window.
     if (win_alloc_firstwin(tp->tp_curwin) == OK)
     {