hi chris - thanks for doing all the work. i installed the patch and updated the tex4ht and tex live repositories.

the | is set to be an escape character (catcode 0) in that context. (in other places, ` is an escape.) all unnecessarily arcane as far as i can tell, but that's how it appears to be.

karl

Having investigated a bit and read Michals email and devised a new test case - see new attachment. The quickest fix appears to be the following:

replace
{t}{\ifmathltx \HCode{ style="text-align:top;" }\fi}
{b}{\ifmathltx \HCode{ style="text-align:baseline;" }\fi}
{c}{\ifmathltx \HCode{ style="text-align:axis;" }\fi}
with
{t}{\ifmathltx \HCode{ align="baseline 1" }\fi}
{b}{\ifmathltx \HCode{ align="baseline -1" }\fi}
{c}{\ifmathltx \HCode{ align="axis" }\fi}

tested in Firefox 30, the result is comparible to what is produced by PDFLatex - baselines of text appear to be aligned the same.

using the command (as per guidelines on the website for producing html/mathml output)

chorler@linux-foxtrot:~/tex4ht-text-align> htlatex tftalign.tex "xhtml,mathml,mozilla" -cmozhtf -cvalidate

the resulting html / xml file has elements within with style attribute css of "text-align:axis;"

The W3 CSS validator reports this as an invalid value for text-align (and I confirmed this by checking the spec and various mailing list archives).

I'm attaching a simple example latex file that exhibits the problem (cut down from a much larger document with several occurences of the problem, I can upload this on request).

The two files of interest in the distribution appear to be:

chorler@linux-foxtrot:~/tex4ht-text-align> rpm -ql texlive-tex4ht | xargs -I {} grep -l 'text-align:axis' {}
/usr/share/texmf/tex/generic/tex4ht/html-mml.4ht
/usr/share/texmf/tex/generic/tex4ht/mathltx.4ht

chorler@linux-foxtrot:~/tex4ht-text-align> grep -n 'text-align:axis' /usr/share/texmf/tex/generic/tex4ht/html-mml.4ht /usr/share/texmf/tex/generic/tex4ht/mathltx.4ht
/usr/share/texmf/tex/generic/tex4ht/html-mml.4ht:96: {c}{\ifmathml \HCode{ style="text-align:axis;\border:lines
/usr/share/texmf/tex/generic/tex4ht/mathltx.4ht:151: {c}{\ifmathltx \HCode{ style="text-align:axis;" }\fi}
chorler@linux-foxtrot:~/tex4ht-text-align>