bug#4879: Crash in xmenu_show

[Juri Linkov]

In a non-toolkit X build GNU Emacs 23.1.50 (x86_64-pc-linux-gnu)
steps to reproduce the crash:

1. emacs -Q
2. Type `C-x C-f'
3. Click on the `Minibuf' top-level menu.

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f146c4497a0 (LWP 31459)]
0x000000000047028f in xmenu_show (f=0x11abbb0, x=383, y=10, for_click=1,
        keymaps=1, title=10721059, error=0x7fff74478630) at xmenu.c:2738
2738                  bcopy (SDATA (item_name), item_data,

I've tracked and narrowed the cause of this crash to a change
between 2009-09-10 and 2009-09-11.

-- 
Juri Linkov
http://www.jurta.org/emacs/