bug#44824: 27.1; Org export as pdf and open file does not open it

[Maxim Nikulin <m.a.nikulin@gmail.com>]

On 30/01/2021 20:49, Eli Zaretskii wrote:
>>
>>> How about asking the xdg-open developers to help us figure out the
>>> reason?
>>
>> I do not think, it is xdg-open problem. It just calls kde-open5 that
>> spawns actual handler and immediately exits.
> 
> I didn't say it was their problem, I suggested to ask them to help us
> understand why xdg-open doesn't work in those cases, under the
> assumption that they are familiar with their code better than us.

What kind of help do you expect from xdg-open developers? It is a shell 
script, you could easily inspect it. I have posted already a command how 
to trace its execution. However currently I am almost sure that it 
merely calls 'kde-open5 /tmp/file.pdf'. The problem is that emacs does 
not expect that kde-open5 and thus xdg-open exits instantly. The 
question could be addressed to KDE developers, but unlike the issue with 
temporary files, in my opinion, pty+SIGHUP problem should be fixed in 
org mode. Some convenience function in emacs core would be nice but org 
mode is compatible with older emacs releases. Thus the only option is to 
change the org-open-files function.