Re: [AUCTeX-devel] preview-latex, dvipng, and LyX

[Angus Leeming]

David Kastrup wrote:
>> However, in recent versions of preview-latex and dvipng the output
>> devised for LyX's sake gets corrupted in the following way:
>>
>> $ dvipng ...
>> This is dvipng 1.7 Copyright 2002-2005 Jan-Ake Larsson
>> [1 (preview-latex version 11.81) depth=6 height=16]
>>
>> this output confuses the script LyX uses for generating preview
>> snippets, which, instead, is expecting an output like this:
> 
> A lesson is learnt, but the damage is irreversible.
> 
> I mean, dvipng and preview.sty have been released in this manner, so
> there is no sane around letting LyX detect this string and deal with
> it.  That's the only way to minimize the impact, even if dvipng get
> changed again in the next version to give this information in a
> different way.  So I am copying the LyX developer list with this mail:
> they will have to be a part of damage control.

Hi, David!

Damage control from this side is easy: no version of LyX has been released
that uses dvipng. (That will be part of the upcoming 1.4.0 release.) That
means we can jump through whatever hoops you choose to present us with ;-)

The obvious solution is to add a flag to dvipng
  --LyX
that is used to swap the existing BE_NONQUIET for BE_VERBOSE

>> A second problem that I noticed is that when a font is missing and
>> mktexpk (or alike) gets called to generate it, its stdout gets
>> intermixed with that of dvipng, causing a similar (but worse) confusion.
>>
>> Is it possible to have the stdout of those helper programs redirected to
>> stderr?
> 
> The latter would actually be useful for preview-latex as well, only
> that it would be nice to direct the output completely elsewhere (Emacs
> does not capture stderr separately): I often have to run preview-latex
> several times when new fonts get generated, because the font
> generating output confuses it.

Perhaps one reasonable solution would be to add a flag to dvipng
  --redirect_externals_stdout_to_stderr

Or somesuch ;-)

-- 
Angus