[tex4ht] Bad interaction with bookmark.sty

[Michal Hoftich]

Dear Francis,

>
>Entering dvipng-bug.lg
>System call: dvipng -q -T tight -D 144 -bg Transparent -pp 2:2 dvipng-bug.idv -o dvipng-bug0x.png >/dev/null
>sh: line 1:   958 Floating point exception(core dumped) dvipng -q -T tight -D 144 -bg Transparent -pp 2:2 dvipng-bug.idv -o dvipng-bug0x.png > /dev/null
>--- Warning --- System return: 34816

There is no support for the Bookmark package in TeX4ht, but I think that 
this issue is not caused by TeX4ht anyway, as it passess content that is 
converted to images directly from the DVI file. So there must be some 
problem with the code that Bookmark writes to the DVI output and that 
causes error in Dvipng. Fortunatelly, it is ibviously not a fatal error 
and the PNG image is produced anyway. 

There are two possible fixes. First is to use another driver that 
Bookmark uses. Try to put the following line before 
\usepackage{bookmark}:

\def\BookmarkDriverDefault{dvipdfm}


It seems to work without errors.

Second possibility is to use Dvisvgm instead of Dvipng. It will create 
SVG images instead of PNG. SVG images should have better quality than 
PNG, so it is a good idea to use them anyway. Try this:

make4ht dvipng-bug.tex "svg"

Best regards,
Michal