latexdiff-vc: generate .bbl files before calling latexdiff

[cousteaulecommandant]

My git project does not track the .bbl files, which made sense at the time of creating it since those files are a product, not a source. As a result, latexdiff-vc fails to generate the bibliography and all references appear as [??].

This patch is a quick and ugly hack I made into the latexdiff-vc code (as downloaded from CTAN, which seems to be slightly different from the one here on github) that calls bibtex into $file1 and $file2 in order to generate the .bbl files before calling latexdiff. However it will probably need some work before being ready to be merged:

• The code should probably check some conditions (such as $flatten and/or $run) before calling bibtex, but I was not sure what would be the way to go. Or maybe the whole block should be moved inside the if ( defined($flatten) ) parts where $olddir and $newdir are declared.
• Maybe [pdf]latex should be called with -draftmode in order to improve the speed (then again, maybe this should be done on ALL calls to $CFG{LATEX} except the last one), but I don't know if this option is latex-specific and thus unsupported by other LaTeX compilers (then again, this is probably no different for --interactive=batchmode as well).
• The documentation should be changed accordingly.
• I included cd '$fileNpath'; in the latex-and-bibtex call I added because otherwise LaTeX complained about relative '\input's; not sure if this was the most elegant way to go but it Just Works™.
• I modified the way $olddir and $newdir are generated, because I was having trouble when calling pdflatex on /tmp/me7swkOS1w/latexdiff-vc-HEAD~1/tex/main.tex because of the damned ~. On second thought, maybe having done cd to that directory first and then calling the latex and bibtex commands without the path would have been a better option. (I hope nobody uses this for comparing commits HEAD~2 and HEAD^2 for example... maybe this wasn't such a good idea after all.)

Please do not consider this as a ready-to-use PR but rather as a suggestion for improvement; as I said it was an ugly hack which will likely need some work and reviewing before being ready (in fact my original idea was to report this as a regular issue, but the patch seemed more convenient). Feel free to ditch the whole PR if you like the idea but prefer to rewrite it from scratch :)

I tested the program with my particular use case and it worked, but I didn't perform extensive testing (I did this in a couple of hours; I just learned about this software today... by the way, kudos to the creators!)

[cousteaulecommandant]

I have eventually built my own replacement shell script for latexdiff-git, with bibtex, and whole repository snapshot.
https://gist.github.com/cousteaulecommandant/d580f7fd966fa9ab143e919c01f01c61

Specifically, the "whole repository snapshot" feature is nice for my current project, since my "main.tex" is not in the top directory but inside tex/, while the images are in img/, and all .tex files refer to other files relatively to this tex/ directory, so I need to cd it before building.
The script will create a snapshot of the whole project rather than only the tex/ directory, and then cd to tex/ in the snapshot and call bibtex there.
Additionally, if second commit hash is omitted, it copies all the files rather than working on the actual project directory.

(The script is not a fully featured replacement for the current latexdiff-vc Perl script, but it could give some ideas.)

[briochemc]

This looks like a good solution to my uneducated self for those, like me, who did not version-control their .bbl files. @ftilmann have you considered including this into latexdiff-vc?

[ftilmann]

Thank you for reminding me of this old suggestions. As the merge request still needed some work according to the OP I had not immediately tackled this and then it dropped off the radar. Unfortunately, I am again quite busy, and it will foreseeable be a few months until I can look into feature request issues.

[ftilmann]

Six and a half years later ... this idea is finally implemented. See man page for some additional advice on this.