Fix undefined behavior in pixel get/set routines #4141
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The unit tests only seem to exercise the UB in set_pixel_color, but I believe the same issue is present in get_pixel_color. There is no guarantee that the incoming pixel buffer is aligned, so casting it to a larger integer with alignment requirements can issue an unaligned load. I've unified and simplified the LE/BE implementation divergence as much as possible. memcpy() should compile to roughly the same asm as a direct assignment. Tested on LE and BE. Should fix pygame#1313
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The unit tests only seem to exercise the UB in set_pixel_color, but I believe the same issue is present in get_pixel_color. There is no guarantee that the incoming pixel buffer is aligned, so casting it to a larger integer with alignment requirements can issue an unaligned load.
I've unified and simplified the LE/BE implementation divergence as much as possible. memcpy() should compile to roughly the same asm as a direct assignment. Tested on LE and BE.
Should fix #1313