We should use `FILE *` instead of `FILE*` or `(FILE*)`, consistently,
as we should for all other pointer types. Moreover, when we refer to
standard stdio file objects in comments and in documentation, we should
use the term "FILE objects" consistently.
Lastly, we clarify in a comment in example.c that `PNG_STDIO_SUPPORTED`
is true only when the stdio support is both available in the system and
accessible in the user's libpng build.
This is a cherry-pick of commit c63c5463903014c904b540216c2784023fb8c1c8
from branch 'libpng18'.
Reviewed-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
pngimage: The code simply exited with a return code of 99 in the event
of a user error including giving pngimage invalid PNG files and an
internal error. It now attempts to clean up the state before doing so,
matching the normal behaviour.
pngimage: Non-ISO use of setjmp(3) corrected.
pngerror.c: Failure to call png_image_free on a false result from a
png_safe_execute function call fixed. This was a regression caused by
the 'volatile' clean-up. Not normally detectable because png_image_free
will often be called by the application.
Reviewed-by: Cosmin Truta <ctruta@gmail.com>
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
This adds APIs to get/set the two remaining new PNG-v3 colour space
chunks. The mDCV API matches that of cHRM. Both chunks support
floating point APIs (all values in the two chunks are real numbers).
Both chunks have a new encoded type, a four-digit-precision fixed-point
number, which cannot be represented in the existing `png_fixed_point`
type, so a `png_uint_32` is used.
Test examples for cICP, cLLI and mDCV are now in pngtest.png, and a
necessary change to the pngunknown.c test program has been made to
accomodate the additions.
Reviewed-by: Cosmin Truta <ctruta@gmail.com>
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Embarcadero's compilers, old (Borland-based) and new (Clang-based),
do have full support for Standard C. The Clang-based compiler is
claiming, through the macro __STDC_VERSION__, to support C99 and C11,
whereas the Borland-based compiler supports ANSI C, as it has for
decades.
However, their run-time library is exposing global functions beyond
the scope of Standard C, for backwards compatibility with the older
Borland products. One of these functions is `randomize`, which clashes
with a function inside pngvalid.c that incidentally has the same name.
Building libpng in "Strict ANSI C" mode, in which all Borland-specific
globals are hidden (e.g. via `bcc32 -A`), would have been a workable
solution for the Borland-based ANSI C compiler, but no such solution
appears to exist for the Clang-based C90/C99/C11 compiler.
Fortunately, renaming a private function inside a test program is a
cost-free alternative fix.
This is a cherry-pick of commit 6184164aa73ee764b1822f44d3db7619cf84f3fa
from branch 'libpng18'.
Disable the check on `interlace_method` inside function `compare_read`
in pngimage.c, if WRITE_INTERLACING is not supported.
If interlaced encoding is disabled inside libpng, the encoded images
are non-interlaced silently and unconditionally. This commit updates
the image comparison to skip the interlace check in the resultant
image; other behavior is still checked.
This is a cherry-pick of commit d9f13d8d846e08b00f6530b7a5fe07039d48c78d
from branch 'libpng18'.
Reviewed-by: Cosmin Truta <ctruta@gmail.com>
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
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>
This corrects the checks to that libpng 10800 does not turn on the
enhanced transform checks in either pngvalid or pngstest. The correct
fix is to change the 10700 code for comments which explain what aspect
or aspects of the transforms are broken (ideally) or at least state that
the transforms are broken.
This is a cherry-pick of commit aec888ab80f5d2241b3515b60f0f9337108fb624
from branch 'libpng18'.
Reviewed-by: Cosmin Truta <ctruta@gmail.com>
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
This adds a new configuration file, 'contrib/conftest/basic.dfa' which
disables unused APIs on a test Linux-based system. So support the
configuration several fixes were necessary in the test programs so that
the tests are skipped correctly when APIs are not available.
The configuration has been tested on a range of common Linux apps
including web browser code (qtwebengine), image processing code (e.g.
ImageMagick) and general display code (X11, Qt5 and Qt6, KDE). Overall
this first step reduces libpng linked code and data size to about 2/3 of
the full configuration.
To use the new test simply copy basic.dfa to 'pngusr.dfa' in the root of
the source directory and build.
Signed-off-by: John Bowler <jbowler@acm.org>
pngimage.c:
Initialize sig_bits on a NOTREACHED path to avoid warnings about using
uninitialized variables.
pngstest.c:
Enlarge buffers and fix signedness to avoid legitimate warnings about
potential buffer overflows.
pngunknown.c:
pngvalid.c:
Use NULL instead of 0 for pointers and apply other style fixes.
makepng.c:
tarith.c:
Apply various style fixes.
Also remove the "last changed" version info from source comments.
The version control system maintains this information automatically.
I got a warning while compiling under Ubuntu 18.04 and gcc 7.4:
"__BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
Quote from the Linux Programmer's Manual:
"To allow code that requires _BSD_SOURCE in glibc 2.19 and earlier and
_DEFAULT_SOURCE in glibc 2.20 and later to compile without warnings,
define both _BSD_SOURCE and _DEFAULT_SOURCE."
As per the const correctness rules, top-level const-ness of data
in automatic scopes does not propagate outside of these scopes
(unlike const-ness at lower levels, such as pointers to const data).
Previously, const was used liberally, but inconsistently across the
libpng codebase. Using const wherever applicable is not incorrect.
However, _consistent_ use of const is difficult to maintain in such
conditions.
In conclusion, we shall continue to use const only where doing so is
strictly necessary:
1. If a function guarantees that it will not modify an argument
passed by pointer, the corresponding function parameter should be
a pointer-to-const (const T *).
2. Static data should not be modified, therefore it should be const.
Reference:
Google C++ Style Guide
https://google.github.io/styleguide/cppguide.html#Use_of_const
In v1.6.0, compiler support for const became a requirement.
It should be used consistently. To maintain backwards compatibility,
PNG_CONST is still maintained in deprecated form.
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.
result when integers appear on both sides of a compare. Worked around the
others by forcing the strict-overflow setting in the relevant functions to
a level where they are not reported.
Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
the space.
Worked around some C-style casts from (void*) because g++ 5.4.0 objects
to them.
Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
overflow' check that is on by default with -Wall -Wextra.
This removes the use of a macro containing the pre-processor 'defined'
operator. It is unclear whether this is valid; a macro which
"generates" 'defined' is not permitted, but the use of the work
"generates" within the C90 standard seems to imply more than simple
substitution of an expression itself containing a well-formed defined
operation.
Signed-off-by: John Bowler <jbowler@acm.org>
Remove all currently detected cases of unsigned overflow. Detection is
runtime, so test case dependent. The changes to pngvalid.c eliminate
spurious and probably invalid tests with one while loop exception.
Apart from that and the change to the dependence on the intended
unsigned overflow in pngtrans.c the changes are limited to altering the
meme for an unsigned 'x' from:
while (x-- > 0)
to
for (; x > 0; --x)
This works because, in all cases, the control variable is not used in
the loop. The 'while' meme was, at one time, warn'ed by GCC so it is
probably a good change, for some weird religious value of good.
Signed-off-by: John Bowler <jbowler@acm.org>
In libpng 1.7 pngimage needs to check PNG_WRITE_PNG_SUPPORTED (new in 1.7), not
PNG_WRITE_SUPPORTED because png_write_png can be disabled without disabling
PNG_WRITE_SUPPORTED. Copied the approach from 1.6 pngcp.c (so this still works
in 1.6 as well.)
This adds pngcp to the build together with a pngcp.dfa configuration test; the
test revealed some configuration bugs which are fixed by corrections to the
_SUPPORTED macros.
pngcp builds on all tested configurations and a number of bugs have been fixed
to make this happen relative to the version in libpng 1.7 contrib/examples.
pngcp.dfa will have to be different for 1.7 but pngcp.c should work fine (not
yet tested). pngcp itself is still missing a usage message; this is a
preliminary version, although since it behaves the same way as 'cp' most unoids
shouldn't have a problem using it correctly.
Signed-off-by: John Bowler <jbowler@acm.org>
The SKIP definition needs to come after the png.h include (see all the other .c
files in contrib/libtests) because it depends on PNG_LIBPNG_VER. This commit
puts it in the correct place.
Signed-off-by: John Bowler <jbowler@acm.org>
MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), but it is fine
with it if the conversion is explicitly invoked by a cast.
Signed-off-by: John Bowler <jbowler@acm.org>
Coverity rejects code where an array element count has type size_t, this
elminates the code in question from contrib/libtests/pngvalid.c
Signed-off-by: John Bowler <jbowler@acm.org>