bug#39207: WITH dgb symbols Re: bug#39207: 28.0.50; crash when sending gnus message

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: gijs@hillenius.net,  39207@debbugs.gnu.org
> Date: Wed, 22 Jan 2020 17:58:12 +0100
> 
> (gdb) pp BVAR(current_buffer,enable_multibyte_characters)
> t
> (gdb)
> (gdb) pp BVAR(buffer,enable_multibyte_characters)
> t
> 
> Thereʼs one stray \342 in there, but the rest looks like ASCII. The
> character gnus should be trying to insert is #x2713, which is
> represented as #xE2 #x9C #x93 (\342 \234 \223), so it looks like there
> are some bytes missing.

Where's the gap start address? are you sure \342 is not inside the
gap?

Does Gnus make the buffer unibyte and then multibyte again or
something?  Or maybe it uses some trick to replace a character in a
string, when it inserts the tickmark, and that trick doesn't work with
non-ASCII characters?

If nothing else gives the clue, I think the only way, albeit a hard
one, is to put a watchpoint on the address of that byte in buffer
text, and see which code inserts the byte.