X-Git-Url: https://ncurses.scripts.mit.edu/?p=ncurses.git;a=blobdiff_plain;f=ncurses%2Fbase%2Flib_newwin.c;h=a6c64beaaf4a1c0efc45fde3cb30164e8c9a4568;hp=791d808244bd1ec37cbd321fdd53e4dab61caec1;hb=fe6abf09238512f5a902bc1aeab2263d1e997396;hpb=11dead39816318fe9601e27756b9497caf7ff490

diff --git a/ncurses/base/lib_newwin.c b/ncurses/base/lib_newwin.c
index 791d8082..a6c64bea 100644
--- a/ncurses/base/lib_newwin.c
+++ b/ncurses/base/lib_newwin.c
@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright (c) 1998-2009,2010 Free Software Foundation, Inc.              *
+ * Copyright (c) 1998-2010,2011 Free Software Foundation, Inc.              *
  *                                                                          *
  * Permission is hereby granted, free of charge, to any person obtaining a  *
  * copy of this software and associated documentation files (the            *
@@ -43,7 +43,7 @@
 #include <curses.priv.h>
 #include <stddef.h>
 
-MODULE_ID("$Id: lib_newwin.c,v 1.66 2010/04/24 23:31:18 tom Exp $")
+MODULE_ID("$Id: lib_newwin.c,v 1.71 2011/05/28 21:32:51 tom Exp $")
 
 #define window_is(name) ((sp)->_##name == win)
 
@@ -141,7 +141,11 @@ NCURSES_SP_NAME(newwin) (NCURSES_SP_DCLx
     T((T_CALLED("newwin(%p, %d,%d,%d,%d)"), (void *) SP_PARM, num_lines, num_columns,
        begy, begx));
 
-    if (begy < 0 || begx < 0 || num_lines < 0 || num_columns < 0)
+    if (begy < 0
+	|| begx < 0
+	|| num_lines < 0
+	|| num_columns < 0
+	|| SP_PARM == 0)
 	returnWin(0);
 
     if (num_lines == 0)
@@ -235,10 +239,15 @@ derwin(WINDOW *orig, int num_lines, int num_columns, int begy, int begx)
 NCURSES_EXPORT(WINDOW *)
 subwin(WINDOW *w, int l, int c, int y, int x)
 {
+    WINDOW *result = 0;
+
     T((T_CALLED("subwin(%p, %d, %d, %d, %d)"), (void *) w, l, c, y, x));
-    T(("parent has begy = %ld, begx = %ld", (long) w->_begy, (long) w->_begx));
+    if (w != 0) {
+	T(("parent has begy = %ld, begx = %ld", (long) w->_begy, (long) w->_begx));
 
-    returnWin(derwin(w, l, c, y - w->_begy, x - w->_begx));
+	result = derwin(w, l, c, y - w->_begy, x - w->_begx);
+    }
+    returnWin(result);
 }
 
 static bool