#286 libpng16 fails in make test on aarch64

[Guillaume Gardet]

Failing tests are:
[ 125s] FAIL: tests/pngvalid-gamma-expand16-transform
[ 154s] FAIL: tests/pngvalid-transform

[Guillaume Gardet]

Add pngvalid-transform.log

[Petr Gajdos]

There is

#ifdef PNG_READ_EXPANDED_SUPPORTED
   png_free(png_ptr, png_ptr->riffled_palette);
   png_ptr->riffled_palette = NULL;
#endif

in pngwrite.c nevertheless I have two doubts:

1. why the free is in pngwrite.c; the png_ptr->riffled_palette structure is allocated in png_do_read_transformations() from pngrtran.c and called only from pngread.c

2. why PNG_READ_EXPANDED_SUPPORTED is used in the preprocessor condition; the structure is allocated only only if PNG_ARM_NEON_INTRINSICS_AVAILABLE is defined and this is iff PNG_ARM_NEON_IMPLEMENTATION == 1.

These two doubts resulted in
https://build.opensuse.org/package/view_file/graphics/libpng16/libpng-arm-free.patch?expand=1
and the build now succedes:
https://build.opensuse.org/package/show/graphics/libpng16

Please look at the patch more thoroughly.

[Petr Gajdos]

See for detailed analysis:
https://bugzilla.suse.com/show_bug.cgi?id=1121829