LaTeX: #5181 workaround an RTD issue causes unexpected consequences

[jfbu]

Unfortunately the #5181 fix for RTD issue about doing only 2 pdflatex runs causes problem for documents lacking a general index (created from usage of :index: role or directive).

RTD does things like

pdflatex -interaction=nonstopmode /home/docs/checkouts/readthedocs.org/user_builds/sphinx/checkouts/master/doc/_build/latex/sphinx.tex
makeindex -s python.ist sphinx.idx
pdflatex -interaction=nonstopmode /home/docs/checkouts/readthedocs.org/user_builds/sphinx/checkouts

in place of using the Sphinx Makefile which uses Latexmk and does the automatic number of runs.

#5181 fixes that by anticipating index creation. This patch originated in #3742 which applied only to Sphinx's own documentation. But the overlooked problem at #5181 is that for documents not having indexed terms, that patch will leave the PDF with a dangling "Index" bookmark. Only a third pdflatex run would get rid of it. This problem does not show when PDF build is done by make -C <buildir> all-pdf, but only with only manual invocation of pdflatex as in the above RTD transcript related to Sphinx own documentation.

This means that #5181 will have to get reverted and a better solution found, if any, for 1.8 release.

• OS: Mac
• Python version: 3.6.4
• Sphinx version: 1.8+

Relates:

• PDF builds do not do enough pdflatex runs readthedocs/readthedocs.org#2857
• PDF builds should use Sphinx provided LaTeX Makefile which uses Latexmk (and possibly xindy) readthedocs/readthedocs.org#4454

[jfbu]

Fixed at f0067f4