bug#15570: 24.3.50; Null pointer crash in (ns-convert-utf8-nfd-to-nfc "\377")

[Jan Djärv]

Hello.

We now throw an error.

        Jan D.

9 okt 2013 kl. 20:33 skrev Carsten Bormann <cabo@tzi.org>:

> On Oct 9, 2013, at 18:31, Jan Djärv <jan.h.d@swipnet.se> wrote:
> 
>> The function clearly expects valid UTF-8 as input.  Why is tramp feeding it 
>> invalid UTF-8?    What is tramp trying to accomplish?  What would be the 
>> expected return value on invalid UTF-8?
> 
> I haven't looked at the details yet (that will be easier once the null 
> pointer reference is fixed).
> 
> That needn't stop me from hypothesizing...
> 
> ns-convert-utf8-nfd-to-nfc is used in places where system output might 
> contain Apple's slightly crazy not-quite-NFD file names, so that you can 
> usefully cut and paste them etc. to places that expect the usual 
> not-quite-NFC.  So one should expect a lot of not-really-UTF-8-after-all 
> input to be fed into this thing.
> I'm presuming tramp just feeds whatever it got from the remote system through 
> this to get more useful output e.g. for a directory listing.
> 
> It probably would be useful to have a robust version of this that just chokes 
> on nothing.
> Raising an error on non-UTF-8 input may be a desirable behavior in other 
> places.
> (Crashing Emacs never is.)
> 
> I'm a bit surprised that this bug apparently was around for a number of years 
> already...
> 
> Grüße, Carsten