Add checks inside the private png*.h header files, in order to reduce
unintentional occurences of application backdoors.
Such backdoors might occur, for example, when we make changes to the
internal data structures that might somehow "leak" from the libpng
code into the user code. The applications that use the libpng API must
pretend not to know that these headers exist at all.
Co-authored-by: John Bowler <jbowler@acm.org>
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
This is a major change required by the new PNGv3 colour chunk precedence
rules. It **does not** change the libpng API (png.h) however it changes
the following handling of PNG files:
IFF the PNG file contains colour space information it changes from the
libpng v3 behaviour to the now compulsory PNG v3 behaviour:
1) libpng no longer invalidates colour space chunks because they are
inconsistent.
2) libpng no longer responds to the "png_get_" APIs positively if they
are not present in the PNG but can be deduced from the colour space
chunks that are present.
The leading blank lines are apparently an artefact of an older source
control system. They are not required and they look like accidents,
because starting a source file with a blank line is not a regular habit
of software developers nowadays.
This is a cherry-pick of commit 37cc20add8fb5b83bb5299a26cd3b41e0f776017
from branch 'libpng18'.
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Delete the structure members used in the 16-bit Turbo C memory models.
Delete the PNG_ABORT declaration used in the 16-bit Windows build.
Stop checking macros (e.g. _WINDOWS) predefined by 16-bit Windows
compilers (but do check the __NT__ macro, which was the only one
predefined by ancient Windows NT compilers).
Move deallocation of riffled_palette from png_write_destroy to
png_read_destroy. The reader (not the writer) is the owner of
riffled_palette.
Move allocation and initialization of riffled_palette from
png_do_read_transformations to png_init_palette_transformations.
Allow riffled_palette inside png_struct only if the ARM Neon
optimizations are enabled.
Rename png_riffle_palette_rgba to png_riffle_palette_rgba8, etc.,
to better indicate the strict applicability of these routines.
Fix an unused parameter warning in the build configurations where
riffled palette optimization is not enabled.
Fix indentation.
In v1.6.0, size_t became a required type. It should be used
consistently. To maintain backwards compatibility, png_size_t
is still maintained in deprecated form.
In libpng 1.6 zlib initialization was changed to use the window size in the zlib
stream, not a fixed value. This causes some invalid images, ones where CINFO is
too large, to display 'correctly' if the rest of the data is valid. This
provides a work-round for zlib versions where the error arises (ones that
support the API change to use the window size in the stream).
Signed-off-by: John Bowler <jbowler@acm.org>
prefixing This adds an API to set optimization options externally,
providing an alternative and general solution for the non-portable
run-time tests used by the ARM Neon code. It also makes those tests
compile and link on Android.
The order of settings vs options in pnglibconf.h is reversed to allow
settings to depend on options and options can now set (or override) the
defaults for settings.
management system (CMS). In practice it is not possible to obtain cHRM
information reliably using just the end-point tags because they do not exist
in the vast majority of profiles. Instead it is necessary to run the endpoints
through the ICC colorimetric intent transform (as described in the v4
spec). Since this is likely to be too much code inside libpng for too
little gain (it implies a fairly complete CMS implementation) the code
has been changed to allow an external CMS to be used. This code is
temporarily disabled until a suitable set of test cases using one or more
external CMS implementations have been implemented.
Glenn thought the "adopted" were typos and changed them all to "adapted".
This reverts the spelling and adds parenthetical comments when each
word first appears in png.h.
