[luatex] [lltx] [tex-live] Location of recorder file

[Philipp Stephani]

Am 15.05.2011 um 12:38 schrieb Ulrike Fischer:

> Am Fri, 13 May 2011 13:41:32 +0200 schrieb Philipp Stephani:
> 
>>> I think, the file name interfaces should be transparent
>>> in the sense, that all characters are supported and
>>> the user is only hit by the restrictions of the operating
>>> system or the file system, but not by artificial restrictions
>>> by the software inbetween.
> 
>> I agree, but this will never happen: try to use a Unicode file
>> name on Windows in any engine ... even though they are perfectly
>> legal as far as the operating system is concerned,
> 
> Which reminds me this news:
> 
> http://www.heise.de/security/meldung/Rueckwaerts-wird-ein-Virus-draus-1242127.html
> (german with a link to an english article)
> 
> So to give you some more headaches: Did someone try what happens (in
> luatex) with file names which do contain 0x202E (right-to-left
> override) und 0x202B (right-to-left embedding)?

Well, nothing (I don't have to try it, I *know* it). These characters are just ordinary Unicode characters that don't trigger any different interpretation from other Unicode characters. The program and the kernel see nothing but a sequence of UTF-16 code units (on Windows) or 8-bit code units (most Unix-like systems). The directionality of a text matters only to the visual interpretation, i.e., the text rendering engine. Compiling such a document leads to funny output on the (OS X) console, but causes no harm.
Besides, this is not a bug or security hole, it's an intended and correct implementation of the Unicode bidirectional algorithms.