bug#43395: memory leaks

[Jean Louis <bugs@gnu.support>]

* Madhu <enometh@meer.net> [2020-11-10 04:27]:
> [Test case follows. Sorry Drew for trying to post to help-gnu and
> debbugs simultaneously, but this is my third attempt at sending this
> test case - I've tried sending it to debbugs.gnu.org and to
> gmane.emacs.help newsgroup - and my messages have been dropped]
> 
> 
> * Madhu <m35z8gise6.fsf@leonis4.robolove.meer.net> :
> Wrote on Mon, 14 Sep 2020 15:36:57 +0530:
> > The numbers I reported by garbage-collect do not account for the memory
> > usage. FWIW I've posted that info again at
> > https://debbugs.gnu.org/cgi/bugreport.cgi?bug=43395
> 
> I found test case for this bug and I sent mail to 43395@debbugs.gnu.org,
> and qmail told me that the mail was accepted:
> delivery 1: success:
> 209.51.188.43_accepted_message./Remote_host_said:_250_OK_id=1kc8Bf-00061T-3u/
> But the bugreport didn't show up on gnu.emacs.bug.
> 
> Here is the test case:
> 
> #+BEGIN_SRC
> $ cat > f.c
> #include <stdio.h>
> int
> main()
> {
>   char c = ' ';
>   while (c != 'q' && c != 'Q')
>     {
>       fprintf(stdout, "Press q then enter to quit: ");
>       c = fgetc(stdin);
>     }
>   return 0;
> }
> ^D
> 
> $ gcc f.c
> $ emacs -Q
> #+END_SRC
> 
> M-x shell-command ./a.out
> 
> Then the process hangs. But Emacs' memory grows unbounded.
> 
> WARNING. Be careful to interrupt it with ^G before the OOM killer
> kicks in.  If you have swap you may lose control of your machine
> indefinitely.
> 
> After you interrupt the sub process, Emacs is left with unreclaimed
> gigabytes of RSS
> 
> Please let me know if you can reproduce this

Me I have been testing now. It all blocks. Then I had to switch to
console from X to kill process.

I can see memory is not reclaimed graphically. Not practically. I have
graphical indicator.

This same things happens from time to time in Emacs. Exactly like you
say when I have swap I may lose control of machine. Then I had to
power off with the hard key. Bad.

I hope this can be resolved.