in pngmem.c; pngvalid would attempt to call png_error() if the allocation
of a png_struct or png_info failed. This would probably have led to a
crash. The pngmem.c implementation of png_malloc() included a cast
to png_size_t which would fail on large allocations on 16-bit systems.
the namespace. Added png_get_current_row_number and
png_get_current_pass_number for the
benefit of the user transform callback.
Added png_process_data_pause and png_process_data_skip for the benefit of
progressive readers that need to stop data processing or want to optimize
skipping of unread data (e.g. if the reader marks a chunk to be skipped.)
The changes include support for function attributes in VC in addition to
those already present in GCC - necessary because without these some
warnings are unavoidable. Fixes include signed/unsigned fixes in
pngvalid and checks with gcc -Wall -Wextra -Wunused.
VC requires function attributes on function definitions as well as
declarations, PNG_FUNCTION has been added to enable this and the
relevant function definitions changed.
Fixed point APIs are now supported throughout (no missing APIs).
Internal fixed point arithmetic support exists for all internal floating
point operations.
sCAL validates the floating point strings it is passed.
Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
Two new APIs exist to get the number of passes without turning on the
PNG_INTERLACE transform and to get the number of rows in the current
pass.
A new test program, pngvalid.c, validates the gamma code.
Errors in the 16 bit gamma correction (overflows) have been corrected.
cHRM chunk testing is done consistently (previously the floating point
API bypassed it, because the test really didn't work on FP, now the test
is performed on the actual values to be stored in the PNG file so it
works in the FP case too.)
Most floating point APIs now simply call the fixed point APIs after
converting the values to the fixed point form used in the PNG file.
The standard headers no longer include zlib.h, which is currently only
required for pngstruct.h and can therefore be internal.
(Patches by John Bowler)
