[Bug-AUCTeX] bug#19121: bug#19121: bug#19121: AUCTeX should report an error if selected viewer fails

[David Kastrup]

Mosè Giordano <address@hidden> writes:

> Hi Davide,
>
> 2014-11-20 16:07 GMT+01:00 Davide G. M. Salvetti <address@hidden>:
>> Package: auctex
>> Version: 11.83
>> Severity: normal
>> Usertags: bugs.debian.org/409795
>>
>> Neither `C-c C-c', nor `C-c C-v', nor `tool-bar view' appear to report
>> any error if the viewer selected by `TeX-view-program-selection' isn't
>> installed.
>>
>> It would be useful if AUCTeX would check if the selected viewer is
>> installed on the system, falling back to some other viewer if available;
>> at a minimum, however, AUCTeX should give some clue to the user about
>> the failure to start a viewer.
>>
>> This bug has been originally reported by a Debian user: see
>> <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=409795>, in
>> particular items marked `0' and `2' by the original submitter.
>
> The attached patch addresses this problem: it adds a third, optional,
> element to `TeX-view-program-list' and
> `TeX-view-program-list-builtin', with the name of the executable
> associated to that viewer and checks inside `TeX-view-command-raw' if
> that executable exists.  I'm not very fond of this solution because it
> needs to add another element to a widely customized variable (although
> the element is optional, so it won't break backward compatibility),
> but I have no other idea to fix it.
>
> Does someone have other suggestions?

The only alternative I see is not to detach the viewing process (or you
won't get any information about the process).  You'd want specially
named process buffers for View/Compile/etc then in order to avoid "a
compilation is in progress.  Abort?" prompts and so on.  Changing to a
detached process, IIRC, solved a number of headaches.  It might be
possible to get rid of most of them in some other way.  However, having
several viewers into the same document open would then likely not be
workable.  Also working with source specials and readjusting the
position, which tends to require another call of the same executable
without killing the previous one, would likely get into trouble.

-- 
David Kastrup