bug#11138: 23.3; on Windows, message-box does not display line breaks in the message

[Eli Zaretskii]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Sat, 31 Mar 2012 23:36:01 +0200
> Cc: Drew Adams <drew.adams@oracle.com>, 11138@debbugs.gnu.org, 
> dpchiesa@hotmail.com
> 
> On Sat, Mar 31, 2012 at 20:06, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > The Windows port doesn't really have an implementation of a message
> > box, it just pops up a menu.  And in a menu, each item is one line.
> 
> And some checking for excessive length is missing, BTW:
> 
> emacs -Q
> M-: (message-box (make-string (/ most-positive-fixnum 2) ?a) "") <RETURN>
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x754f8dd2 in strcat () from C:\Windows\syswow64\msvcrt.dll
> (gdb) bt
> #0  0x754f8dd2 in strcat () from C:\Windows\syswow64\msvcrt.dll
> #1  0x64c9000c in ?? ()
> #2  0x012b68f4 in fill_in_menu (menu=0x37640627, wv=0x9f1740) at 
> w32menu.c:1564

This crash should be fixed in trunk revision 107723.  Now even your
crazy test case doesn't crash, just says that it ran out of memory
after a while (kids, don't try that at home).

Btw, it looks like MS-Windows menus cannot have strings longer than
64K, although I cannot find this documented anywhere.