Set the PNG_FREE_PCAL flag immediately after the allocation of the
first pCAL buffer, so that, if any one of the subsequent allocations
fail, all pCAL buffers still get deallocated by png_free_data.
Also reorder the initialization of other PNG_FREE_ flags (without
altering the semantics) to improve the overall consistency inside
the pngset.c module.
Co-authored-by: Philippe Antoine <contact@catenacyber.fr>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
This leak was discovered by OSS-Fuzz.
The old structure of the code was along the lines of:
allocate trans_alpha;
if (problem) {
// Jumps away from this function
png_warning("tRNS chunk has out-of-range samples for bit_depth");
}
mark trans_alpha as to-free;
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
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.
in pngwrite.c, and made various other fixes to png_write_eXIf().
Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif
to arguments for png_get_eXIf() and png_set_eXIf().
