Re: [ft-devel] Updates for GF driver.

[Werner LEMBERG]

>>> * Robustness: Please have always in mind that malformed GF files
>>>   must be either sanitized or properly rejected.  Not sure whether
>>>   this is an issue, but GF commands like `paint3' can handle quite
>>>   large values...
>>
> 
> I have already added checks for `post_post` instruction which checks
> for GF_ID and returns `Invalid_File_Format` if not found so, and
> some more checks which checks for GF files' validity in
> `gf_load_font`.  Similar to what done in Vflib.  Do you suggest
> anything more?

I don't know yet.  I would have to study the GF format in detail to
find out such issues – I forward this to you :-)

>>> * There is no code yet in `gf_load_font' to recognize the GF
>>>  format (returning `not a GF font' otherwise).
> 
> Isn't this same as done above, for `Invalid_File_Format`?

No, it's not.  If the format is not recognized, this is, the GF driver
has decided that the font in question is not a GF font, the driver
should return `Unknown_File_Format'.

Later on, if the GF drvier has come to the decision: `Yes, this is
definitely a GF font', all problems that can't be sanitized should
lead to `Invalid_File_Format' (or one of the more specific error
codes).


    Werner