Re: [ft] FT_Done_Face Should Not Return An Error

[Werner LEMBERG]

>> IMHO, `FT_Done_Face' shouldn't return an error code
>> at all.
> 
> Glad you finally agree. So how to fix it?

IMHO, there is nothing to fix.

> * For backward compability, it should continue to return FT_Err_Ok.

It should return what it already returns.

> * So what should the code do if the FT_List_Find call returns NULL?
>   I think it should print a message to stderr and abort the program.

I don't want that.  I still think that a library should return control
to the caller even if something weird is happening.  Just imagine a
Windows program where output to stderr is not displayed.  You rather
have to give control back to Windows so that it can create a useful
dialogue window.

> Ignoring the internal consistency failure is not really a good idea.
> It is very likely an indication that memory blocks are screwed.  So
> if the code just tries to keep going, it could hit a segfault later
> on, or otherwise behave unpredictably.

Why do you think, from a user's point of view, that aborting is better
than segfaulting?  In both cases the point of failure is not where the
error gets triggered.  Only a tool like `valgrind' can give more
information to find out where the memory got corrupted.

> And then the programmer is left scratching their head as to what
> went wrong.  By reporting the problem as close as possible to the
> point of its discovery, you maximize the chance that it can be found
> and fixed.

I don't think so.  If you get a crash, the first action usually is to
run the program within a debugger or a tool like `valgrind' (assuming
you have compiled with activated debugging support).

What I can imagine, however, is to add `assert' statements.  FreeType
has very few of them; maybe there should be more to better check
consistency.


    Werner