Fix bug#17510 with a pointer freed more than once (Cygwin-w32-build).

* src/w32term.c (x_delete_display) [CYGWIN]: Don't free
dpyinfo->w32_id_name, to make sure it doesn't get freed more than
once.

src/ChangeLog

+2014-05-24  Ken Brown  <kbrown@cornell.edu>
+
+	* w32term.c (x_delete_display) [CYGWIN]: Don't free
+	dpyinfo->w32_id_name, to make sure it doesn't get freed more than
+	once.  (Bug#17510)
+
 2014-05-24  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* xdisp.c: Bind inhibit-quit during pre-redisplay-function.

src/w32term.c

@@ -6426,7 +6426,11 @@ x_delete_display (struct w32_display_info *dpyinfo)
     if (dpyinfo->palette)
       DeleteObject (dpyinfo->palette);
   }
+  /* Avoid freeing dpyinfo->w32_id_name more than once if emacs is
+     running as a daemon; see bug#17510. */
+#ifndef CYGWIN
   xfree (dpyinfo->w32_id_name);
+#endif
 
   w32_reset_fringes ();
 }