Re: [Gnumed-devel] Latex failure

[Karsten Hilbert]

On Thu, Nov 29, 2012 at 11:51:44PM +0100, Karsten Hilbert wrote:

> > it is blackslash in subjective field \ that has resulted
> > in failed pdf generation. I removed it from temp\gnumed tex
> > file and i could generate the pdf. No doubt about the
> > problem. I would send the tex file once i could get it on
> > internet
> 
> Well, you found a bug of sorts :-)
> 
> > {\small S} & {\small Follow up. Stool frequency 2/day. No blood. Abdominal 
> > discomfort+, Fever + mild. Received crocin$\backslash$O2 with relief} 
> > \tabularnewline
> 
> What GNUmed does (did) is replace a literal "\" with the
> string "$\backslash$". "\backslash" is one way to say "print
> a \ here" in LaTeX. This command, however, only works in
> what's called Math Mode -- which is started and ended by "$"
> (which, in turn, is why "$" itself is a special LaTeX
> character and needs escaping if needed literally).
> 
> While GNUmed properly inserts "$\backslash$" still *another*
> layer goes over the content _again_ trying to escape special
> LaTeX chars inside data. This double-escaping is what's
> causing the trouble - it escapes the "$"s into "\$"s
> effectively disabling them from starting/ending Math Mode.
> 
> I will investigate where the double-escape comes from tomorrow.

Actually, it turned out not to be double-escaping but rather
a straightforward bug:

        def tex_escape_string(text=None):
                """check for special LaTeX characters and transform them"""

                text = text.replace(u'\\', u'$\\backslash$')
                text = text.replace(u'{', u'\\{')
                text = text.replace(u'}', u'\\}')
                text = text.replace(u'%', u'\\%')
                text = text.replace(u'&', u'\\&')
                text = text.replace(u'#', u'\\#')
                text = text.replace(u'$', u'\\$')
                text = text.replace(u'_', u'\\_')
                text = text.replace(u_euro, u'\\EUR')

                text = text.replace(u'^', u'\\verb#^#')
                text = text.replace('~','\\verb#~#')

                return text

This will *first* replace "\" with "$\backslash$" and *then*
replace "$" with "\$".

That can't work properly :-)

Fixed.

You may want to search your machine for the file
.../client/pycommon/gmTools.py, within that find the
function tex_escape_string and MOVE the line

        text = text.replace(u'\\', u'$\\backslash$')

AFTER the line

        text = text.replace(u'$', u'\\$')

That should do.

Karsten
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