Re: help debugging a segfault

[Sam Halliday]

On Monday, 17 October 2016 21:28:18 UTC+1, Sam Halliday  wrote:
> On Monday, 17 October 2016 21:16:35 UTC+1, Sam Halliday  wrote:
> > Thread 1 "emacs" received signal SIGSEGV, Segmentation fault.
> > re_search_2 (bufp=bufp@entry=0xc2d460 <searchbufs+2912>, 
> > str1=str1@entry=0x597b790 <error: Cannot access memory at address 
> > 0x597b790>, size1=size1@entry=0, 
> >     str2=str2@entry=0x597b790 <error: Cannot access memory at address 
> > 0x597b790>, size2=65565, startpos=646, startpos@entry=623, range=509, 
> >     regs=0xc2c8d0 <search_regs>, stop=1155) at regex.c:4464
> > 4464                      int len = BYTES_BY_CHAR_HEAD (*p);
> ... 
> > Could anybody please shed some light on what could be going wrong? I also 
> > have a core dump file but I have no idea what to do with it, I've never 
> > used gdb in anger.
> 
> Typing "bt" when loading the coredump gives
> 
> (gdb) bt
> #0  0x00007fe8cbfabf5f in ?? ()
> #1  0x00000000005da106 in mapcar1 (leni=11, vals=<optimized out>, fn=40, 
> seq=498) at fns.c:2494
> #2  0xffffffffffffffff in ?? ()
> #3  0xffffffffffffffff in ?? ()
> #4  0xffffffffffffffff in ?? ()
> #5  0xffffffffffffffff in ?? ()
> #6  0xffffffffffffffff in ?? ()
> #7  0xffffffffffffffff in ?? ()
> #8  0xffffffffffffffff in ?? ()
> #9  0x000000000000000b in ?? ()
> #10 0x00000000004ee994 in Finternal_merge_in_global_face (face=2, 
> frame=12113136) at xfaces.c:3669
> #11 0x0000000000000000 in ?? ()

It was suggested to me that this could be 
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=24640 but I was able to reproduce 
with the emacs-25 git branch :-(