Should ask-user-about-supersession-threat be aware of noninteractive ? (emacs -batch)

Should ask-user-about-supersession-threat be aware of noninteractive ? (emacs -batch)

[richard.sharman]

I'm not sure if this is a bug or not.

When running emacs -batch,  if a function modifies a buffer and calls save-buffer and there is another emacs -batch also updating the same file, one of them can call ask-user-about-supersession-threat [in userlock.el].

This causes the emacs process to hang because read-char-choice never returns.  (I have a traceback which I could post but is lengthy (91 levels!);  it ends at pselect and frame 2 is wait_reading_process_output.)

This happened when running make -j 6 and I changed the scenario to not happen,  but I wondered if ask-user-about-supersession-threat should be act upon variable noninteractive.

Or is one supposed to supply a replacement for ask-user-about-supersession-threat if running emacs in batch mode?

Thanks,
Richard

-- 
This e-mail (including any attachments) is for the sole use of the intended 
recipient(s) and may contain information that is confidential and/or 
protected by legal privilege. Any unauthorized review, use, copy, 
disclosure or distribution of this e-mail is strictly prohibited. If you 
are not the intended recipient, please notify Mitel immediately and destroy 
all copies of this e-mail.  Mitel does not accept any liability for breach 
of security, error or virus that may result from the transmission of this 
message.

-- 
This e-mail (including any attachments) is for the sole use of the intended 
recipient(s) and may contain information that is confidential and/or 
protected by legal privilege. Any unauthorized review, use, copy, 
disclosure or distribution of this e-mail is strictly prohibited. If you 
are not the intended recipient, please notify Mitel immediately and destroy 
all copies of this e-mail.  Mitel does not accept any liability for breach 
of security, error or virus that may result from the transmission of this 
message.

Re: Should ask-user-about-supersession-threat be aware of noninteractive ? (emacs -batch)

[Eli Zaretskii]

> Date: Tue, 9 Feb 2016 12:50:57 -0800 (PST)
> From: richard.sharman@mitel.com
> Injection-Date: Tue, 09 Feb 2016 20:50:57 +0000
> 
> I'm not sure if this is a bug or not.
> 
> When running emacs -batch,  if a function modifies a buffer and calls save-buffer and there is another emacs -batch also updating the same file, one of them can call ask-user-about-supersession-threat [in userlock.el].
> 
> This causes the emacs process to hang because read-char-choice never returns.  (I have a traceback which I could post but is lengthy (91 levels!);  it ends at pselect and frame 2 is wait_reading_process_output.)
> 
> This happened when running make -j 6 and I changed the scenario to not happen,  but I wondered if ask-user-about-supersession-threat should be act upon variable noninteractive.
> 
> Or is one supposed to supply a replacement for ask-user-about-supersession-threat if running emacs in batch mode?

Please report this (with that traceback, please) using
report-emacs-bug.  It's possible that
ask-user-about-supersession-threat should always provide an automatic
response in batch mode.

Thanks.