bug#24358: 25.1.50;

[Eli Zaretskii]

> From: Sam Halliday <sam.halliday@gmail.com>
> Date: Tue, 18 Oct 2016 09:16:38 +0100
> 
> Could somebody please let me know how to dig into 0x56e5508 (if
> relevant)? I have never used gdb in anger.

The factor that triggers the bug is the call to malloc, which
causes relocation of buffer text to a different address, while
re_search_2 still uses the (stale) pointer to that text.

So the way to make sure this is the same bug is to see that
(1) there's a call to malloc between entry to re_search_2 and
the crash, and (2) that the value of current_buffer->text->beg
is different before and after the call to malloc.

Thanks.