Re: [ft-devel] Accessing FT_Stream API

[armin]

>>>> Also, I just ran into the issue of `FT_Stream_OpenGzip' requiring 
>>>> the stream to having a valid `memory' field, which is not provided 
>>>> by `FT_Stream_OpenMemory' (for obvious reasons).
>>>
>>> This looks like a bug, both in documentation (which doesn't mention
>>> it) and implementation (which doesn't correctly check for a valid 
>>> `memory' field).
>
> After some thinking I now believe that we have to solve this issue in a
> different way.  A stream should always be created with `FT_Stream_New';
among
> other things it ensures that there is a valid `stream->memory' field.  If
you
> encounter a situation where `memory'
> is NULL it seems that either `FT_Stream_New' wasn't properly called, or
> `stream' wasn't set up correctly.  Can you investigate that?

If I'm not mistaken, one such place is
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/tree/src/base/ftmac.
c#n770 (this is where I got my initial idea from :)) ... there are generally
a few more cases in combination with `FT_Stream_OpenMemory' and possibly
more instances with other initialisation methods.  Do you suggest patching
those cases or just suggesting `FT_Stream_New' as "best practise" in the
future?

> So please commit the `memory' checks but not the documenation fix, which
is an
> internal detail Joe User shouldn't take care of (as Alexei correctly
states).

Tbh, I'm not sure how much these checks help;  if you have half initialised
(non-zeroed-out-first) objects from `FT_Stream_OpenMemory', these checks
won't help (e.g. in `ftmac.c').  Afaik there's no policy about throwing
half-initialised things at `FT_Stream_OpenMemory' (which does not zero-out
anything either).  These NULL-checks are only useful when used on properly
initialised objects which, most likely, stem from `FT_Stream_New' anyways
and don't need those checks.

Please correct me where I'm wrong! :)

Armin