fixed Cygwin+MSVC build errors. The ICC profile handling now includes more
checking. Several errors that caused rejection of the profile are now
handled with a warning in such a way that the invalid profiles will be
read by default in release (but not pre-RC) builds but will not be
written by default. The easy part of handling a cHRM chunk is written,
where the ICC profile contains the required data. The more difficult
part plus guessing a gAMA value requires code to pass selected RGB values
through the profile.
option to pngtest. The "--relaxed" option turns off the benign errors that are
enabled by default in pre-RC builds. makepng can now write ICC profiles
where the length has not been extended to a multiple of 4, and pngtest
now intercepts all libpng errors, allowing the previously-introduced
"--strict test" on no warnings to actually work.
libpng handling of unknown chunks other than vpAg and sTER (including
unsafe-to-copy chunks which were dropped before) and eliminates the
repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
(so the chunks are where libpng would put them).
png_set_keep_unknown_chunks() to be turned off if not required and causes
both read and write to behave appropriately (on read this is only possible
if the user callback is used to handle unknown chunks). The change
also removes the support for storing unknown chunks in the info_struct
if the only unknown handling enabled is via the callback, allowing libpng
to be configured with callback reading and none of the unnecessary code.
support. Now "make check" will succeed even if libpng is compiled with
-DPNG_NO_READ or -DPNG_NO_WRITE. The tests performed are reduced, but the
basic reading and writing of a PNG file is always tested by one or more of
the tests.
errors) and cause it not to fail at the comparison step if libpng lacks support
for writing chunks that it reads from the input (currently only implemented
for compressed text chunks).
compiler issues slightly different warnings from those issued by the
current vesions of GCC. This eliminates those warnings by
adding/removing casts and small code rewrites.
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.
