bug#56553: 29.0.50; ASAN error with fringe bitmaps on NS

[Gerd Möllmann]

> On 2022-07-15,, at 10:23 , Po Lu <luangruo@yahoo.com> wrote:

> Yes, you're right here.  I think that code does want to access the
> individual bytes.

Interestingly, just doing

        const char *bitmap_bytes = (const char *) bits;
        bool bit = bitmap_bytes[byte] & (0x80 >> x % 8);

here results in garbage fringe bitmaps beign displayed.  I'm stumped.

> 
>> The NSBezierPath stuff I don't know.  I gather, from a short look at
>> the docs, that one can "record" stuff that should be drawn in such an
>> object.  The path can then later be used to actually draw.  Looks a
>> tad complicated to me to draw single pixels as a rectangle of size 1,
>> but what do I know...
> 
> Believe it or not, it's the only way to record such a pixel without
> resulting in annoying scaling artifacts from the OS trying to scale the
> image up to monitor resolution.

Good to know.  I guess it's easier to display a PDF on the Mac than an XBM :-).

Thanks!