Subject: bug#22739: 25.0.50; Hangs on revertig buffer

From: Óscar Fuentes <[email-masked]>
Date: Sat, 20 Feb 2016 17:40:35 +0100

Eli Zaretskii <[email-masked]> writes:

>> I'm afraid that the Emacs instance is not resumable anymore. After using
>> the "finish" trick on the previous message, I was unable to interrup
>> Emacs either with C-c on the gdb console (as I did the first time after
>> attaching gdb)
>
> Are you saying that just attaching GDB didn't stop Emacs, and you
> needed C-c to do that?

gdb attached correctly and used C-c on the gdb console to interrupt it
(or it was interrupted automatically when gdb attached to it, I can not
remember for sure), then I obtained the backtrace posted on this thread
and used `finish' to locate the frame that infloops. Obviously, at that
point Emacs was inflooping again and C-c was ignored. Then I sent a
SIGSTOP signal to emacs, which interrupted the process and was able to
obtain the contents of *Messages* from gdb.

>> nor C-z on the Emacs window (as DEBUG suggests.) I sent a SIGSTOP
>> signal to the Emacs process to gain access to the gdb command line
>> and now it can't resume.
>
> What do you mean by "cannot resume"?  What happens if you try?

After executing `c', gdb showed the signal handler. Same when repeated.

> What happens if you kill the GDB process, and then attach another GDB
> to Emacs?

Sorry, the Emacs session is gone now.

Next time I'll try to not use C-g and attach gdb right away.