ctests broken due to a recent commit

[Jean-Marc Lasgouttes]

Le 10/03/2022 à 18:05, Kornel Benko a écrit :
>> I knew it would not be correct on the first try, but it was not that far.
> 
> Nonetheless great job. I have seen that the latex output was missing
> '\usepakage{graphicx}' but was unable to see why.

validate() is something I know much better than the latex() output code. 
But still, I do not see what made iconv complain about bad unicode.

And then there is luck too. For the previous patch, I had to spend a 
long time with valgrind to understand what was going on, and then a long 
time trying to see whether I can avoid that updateBuffer ruins everything.

JMarc