where warnings may be erroneously issued by code-checking applications.
Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.

and translated keyword are no longer issued when these are empty, which
is allowed by the PNG specification.

strip option. pngfix relied on undefined behavior and even a simple change from
gcc to g++ caused it to fail.  The new strip option 'unsafe' has been
implemented and is the default if --max is given.  Option names have
been clarified, with --strip=transform now stripping the bKGD chunk,
which was stripped previously with --strip=unused.
Added all documented chunk types to pngpriv.h

correctly.

for error messages, etc.

chunks known to libpng.

PNG_GAMMA_MAC_18 as parameters for png_set_gamma().

Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
on __ARM_NEON__ from configure time to compile time.  This breaks symbol
prefixing because the definition of the special png_init_filter_functions
call was hidden at configure time if the relevant compiler arguments are
passed in CFLAGS as opposed to CC.  This change attempts to avoid all
the confusion that would result by declaring the init function even when
it is not used, so that it will always get prefixed.

pnglibconf.h, allowing more of the decisions to be made internally
(pngpriv.h) during the compile.  Without this, symbol prefixing is broken
under certain circumstances on ARM platforms.  Now only the API parts of
the optimizations ('check' vs 'api') are exposed in the public header files
except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
decision about whether or not to use the optimizations.

This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
using a compiler that compiles for multiple architectures at one time.

(Andrew Hundt)

descriptions

with the right zlib headers.