Re: [Gnumed-devel] Latex failure

[Karsten Hilbert]

On Thu, Nov 29, 2012 at 06:41:47PM +0000, Vaibhav Banait 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.

The current GNUmed code uses a better method for escaping
which does not rely on Math Mode anymore. I'll backport that
to 1.2 as well.

Cheers,
Karsten
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