Re: [PATCH] XCloseDisplay already calls XrmDestroyDatabase

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

>>>>> On Sun, 17 May 2009 17:40:50 -0400, Stefan Monnier <monnier@iro.umontreal.ca> said:

>>> If we remove the XrmDestroyDatabase call unconditionally, then it
>>> causes a memory leak when used with a newer libX11.  But that would
>>> be better than crashing when used with an older one.

>> Or maybe we can dissociate the resource database from the display
>> before closing it.

>> #ifdef HAVE_XRMSETDATABASE
>> XrmSetDatabase (dpyinfo->display, NULL);
>> #else
>> dpyinfo->display->db = NULL;
>> #endif

>> Then we can ignore the difference of libX11 at least for normal close.

> Sounds OK as well.

Here is a patch.  If it's OK, I'd like to install it before the next
pretest.

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp

Index: src/xterm.c
===================================================================
RCS file: /sources/emacs/emacs/src/xterm.c,v
retrieving revision 1.1025
diff -c -p -r1.1025 xterm.c
*** src/xterm.c	2 May 2009 20:16:58 -0000	1.1025
--- src/xterm.c	18 May 2009 08:00:51 -0000
*************** x_delete_display (dpyinfo)
*** 10613,10625 ****
  	  tail->next = tail->next->next;
      }
  
-   /* Xt and GTK do this themselves.  */
- #if ! defined (USE_X_TOOLKIT) && ! defined (USE_GTK)
- #ifndef AIX		/* On AIX, XCloseDisplay calls this.  */
-   XrmDestroyDatabase (dpyinfo->xrdb);
- #endif
- #endif
- 
    xfree (dpyinfo->x_id_name);
    xfree (dpyinfo->x_dnd_atoms);
    xfree (dpyinfo->color_cells);
--- 10613,10618 ----
*************** x_delete_terminal (struct terminal *term
*** 10740,10745 ****
--- 10733,10752 ----
        x_destroy_all_bitmaps (dpyinfo);
        XSetCloseDownMode (dpyinfo->display, DestroyAll);
  
+       /* Whether or not XCloseDisplay destroys the associated resource
+ 	 database depends on the version of libX11.  To avoid both
+ 	 crash and memory leak, we dissociate the database from the
+ 	 display and then destroy dpyinfo->xrdb ourselves.  */
+ #ifdef HAVE_XRMSETDATABASE
+       XrmSetDatabase (dpyinfo->display, NULL);
+ #else
+       dpyinfo->display->db = NULL;
+ #endif
+       /* We used to call XrmDestroyDatabase from x_delete_display, but
+ 	 some older versions of libX11 crash if we call it after
+ 	 closing all the displays.  */
+       XrmDestroyDatabase (dpyinfo->xrdb);
+ 
  #ifdef USE_GTK
        xg_display_close (dpyinfo->display);
  #else