[AD] bug in getpixel

["Vincent Penecherc'h" <Vincent.Penecherch@xxxxxxxxxx>]

How's that for an attention grabbing subject ? :)

In 24 bit modes, when the last pixel of a memory BITMAP
is right on the end of a page, the assembler getpixel will
trigger a page fault by reading an unaligned int for the
three bytes of the pixel (in the last page) and a random
byte (in the next page) which will then get masked out,
but the damage is done.

I've tried changing the code to either read 3 bytes and
or the results, or read aligned and shift for odd addresses,
but both are slower than the unaligned reads, so I've
just added 1 to the allocated memory for 24 bit BITMAPs.

Not a nice solution, but it works.


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