on alignment increasing pointer casts when -Wcast-align is passed. This
fixes the cases clang warns about either (pngread.c) by eliminating the
casts from png_bytep to png_uint_16p or, for pngrutil.c where the cast
is previously verified or pngstest.c where it is OK by introducing new
png_aligncast macros to do the cast in a way that clang accepts.
to reset the user limits to safe ones if PNG_SAFE_LIMITS is defined.
To enable, use CPPFLAGS=-DPNG_SAFE_LIMITS on the configure command
or put #define PNG_SAFE_LIMITS_SUPPORTED in pnglibconf.h.prebuilt.
(Reverted previous implementation of PNG_SECURE.)
FLOATING_POINT options were switched off, png.h ended up with lone ';'
characters. This is not valid ANSI-C outside a function. The ';'
characters have been moved inside the definition of PNG_FP_EXPORT and
PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration
of the corresponding functions were completely omitted, even though some
of them are still used internally. The result is still valid, but
produces warnings from gcc with some warning options (including -Wall). The
fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION
when png.h is included from pngpriv.h.
Added new "png_structrp" typedef. Because of the
way libpng works both png_info and png_struct are always accessed via a
single pointer. This means adding C99 'restrict' to the pointer gives
the compiler some opportunity to optimize the code. This change allows that.
changes alter how the tricky allocation of the initial png_struct and png_info
structures are handled. png_info is now handled in pretty much the same
way as everything else, except that the allocations handle NULL return
silently. png_struct is changed in a similar way on allocation and on
deallocation a 'safety' error handler is put in place (which should never
be required). The error handler itself is changed to permit mismatches
in the application and libpng error buffer size; however, this means a
silent change to the API to return the jmp_buf if the size doesn't match
the size from the libpng compilation; libpng now allocates the memory and
this may fail. Overall these changes result in slight code size
reductions; however, this is a reduction in code that is always executed
so is particularly valuable. Overall on a 64-bit system the libpng DLL
decreases in code size by 1733 bytes. pngerror.o increases in size by
about 465 bytes because of the new functionality.
