\pdfendlink ended up in different nesting level than \pdfstartlink

Question

I started using showkeys in one of my documents and see this error

\pdfendlink ended up in different nesting level than \pdfstartlink

A bit of google suggests that this "happens when hyperref is used under pdftex and a citation splits across a page boundary". (See: http://tug.org/errors.html).

But this package is only useful at drafting stage where the text is changing frequently i.e. the chance of the error is high. Is there a general way to smoothly use showkeys with hyperref? Thanks.

Answer 1

I figured out the location of the link causing the error using the [draft] option in the hyperref package definition, as explained in this 2002 mailing list post by James A. Bednar:

... when this error occurs, write down the page number where pdflatex aborted, then add the "draft" option to hyperref:

\usepackage[draft]{hyperref}

and recompile the document. PDF output will now be generated, the problematic link should be the citation whose latter half begins the page where pdflatex aborted. After slightly rearranging the text to avoid the linebreak, the [draft] option can be removed.

(I tried user22326's useful suggestion to use the [debug] option in the hyperref package definition, however, this didn't help me in finding the location (in the log, or in the latex file) of the link causing the error. Not even after I figured it out using the draft option solution.)

Answer 2

I have just resolved a similar error by putting the offending citation inside an \mbox. You just have to figure out where is the offending citation, for example, by successively commenting and uncommenting your LaTeX file. It worked for me, so I hope this works for anyone else, as unfortunately, the error message is not helpful (as usual in LaTeX).

Answer 3

I use an alternative, which gives a better rendering to me:

\bibliographystyle{your-format}
\interlinepenalty=10000
\bibliography{your-bibtex-file}

It prevents breaking a citation across two pages. Hence, hyperlinks in a citation cannot be broken. It solves two problems at the same time for me.

Answer 4

Sometimes, the links are created by the bibliography, from items with URL fields. A solution that helps in this case and preserves clickable links is to make sure that each \bibitem is typeset without column or page breaks:

\let\oldbibitem\bibitem
\def\bibitem{\vfill\oldbibitem}

A \vfill rubber length is inserted before each \bibitem. This produces ugly output that is nevertheless "good enough" for a draft. Don't forget to remove this hack just before releasing the document.

(For a general solution, we also need to Wrap natbib macros \citep and \citet. No luck with this one yet.)

Answer 5

Without an MWE, it's hard to say something that we can be sure will fix the problem. I haven't, for the obvious reason, tested any of what follows.

If the problem arises when:

1. showkeys is used near the end of the document, then you can force a page eject if the command is used near the end of the document. E.g.: \let\urshowkeys=\showkeys \def\showkeys{\needspace{5ex}\urshowkeys} (requires needspace package).
2. Likewise if it occurs when a hyperref is used near the end of the document.
3. If it occurs because the link is split between the main body and the margin text, then the best thing might be to write your own wrappers that puts the label in the body text, so that the problem doesn't arise. This should be easy, and I'm guessing this is an acceptable workaround given that the text is a draft.

Answer 6

See this issue. A workaround is to let links break across pages by adding this to the preamble:

\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{\errmessage{\noexpand patch failed}}
\makeatother

Answer 7

Place \hypersetup{draft} before \begin{document} will solve the problem.

Answer 8

The following two lines in the preamble solve the problem:

\let\oldhref\href
\renewcommand{\href}[2]{\oldhref{#1}{\hbox{#2}}}

Answer 9

In my case, the problem was a reference that was stretching over two pages like Miller (2019) where Miller was on page k and (2019) was on page k+1.

Answer 10

In one case the offending link seemed to be coming from the bibliography link generation. This might help:

sed '/\\bibitem/ s/ /~/g' file.bbl > tmp.bbl && mv tmp.bbl file.bbl