pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
now that png_ptr->buffer is inaccessible to applications, the special
handling is no longer useful.
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.
Fixed a memory overwrite bug in simplified read of RGB PNG with
non-linear gamma Also bugs in the error checking in pngread.c and changed
quite a lot of the checks in pngstest.c to be correct; either correctly
written or not over-optimistic. The pngstest changes are insufficient to
allow all possible RGB transforms to be passed; pngstest cmppixel needs
to be rewritten to make it clearer which errors it allows and then changed
to permit known inaccuracies.
The API is extremely inaccurate for sRGB conversions because it uses an 8-bit
intermediate linear value and it does not use the sRGB transform, so it
suffers from the known instability in gamma transforms for values close
to 0 (see Poynton). The net result is that the calculation has a maximum
error of 14.99/255; 0.5/255^(1/2.2). pngstest now uses 15 for the
permitted 8-bit error. This may still not be enough because of arithmetic
error.
to the background parameter of png_image_finish_read. The --background
option is now done automagically only when required, so that commandline
option no longer exists.
Also some layout regularization and removal of introduced tab characters
(replaced with 3-character indentation). Obsolete macros identified by
autoupdate have been removed; the replacements are all in 2.59 so
the pre-req hasn't been changed. --enable-werror checks for support
for -Werror (or the given argument) in the compiler. This mimics the
gcc configure option by allowing -Werror to be turned on safely; without
the option the tests written in configure itself fail compilation because
they cause compiler warnings.
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.
those uses of png_memcpy that were doing a simple assignment to assignments
(all those cases where the thing being copied is a non-array C L-value.)
Added some error checking to png_set_*() routines and removed the
reference to the non-exported function png_memcpy() from example.c. Fixed
the Visual C 64-bit build - it requires jmp_buf to be aligned, but it had
become misaligned.
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.
