On certain operations, such as iterating through all objects and
adding new indirect objects, walk through the entire object structure
and explicitly resolve any indirect references to non-existent
objects. That prevents new objects from springing into existence and
causing the previously dangling references to point to them.
There were a few places in the code that were checking that a pointer
wasn't null before deleting it, even though C++ has always allowed
delete 0. Most of the code did not perform these checks.
Implement a TokenFilter class and refactor Pl_QPDFTokenizer to use a
TokenFilter class called ContentNormalizer. Pl_QPDFTokenizer is now a
general filter that passes data through a TokenFilter.
* Add support for PCLm using setPCLm() and writePCLm() methods in
QPDFWriter.hh and QPDFWriter.cc
* Add a function writePCLmHeader() for PCLm header in QPDFWriter
There is no need for a --precheck-streams option. We can do the
precheck without imposing any penalty, only re-encoding the stream if
it fails the first time.
This commit adds several API methods that enable control over which
types of filters QPDF will attempt to decode. It also adds support for
/RunLengthDecode and /DCTDecode filters for both encoding and
decoding.
When requested, QPDFWriter will do more aggress prechecking of streams
to make sure it can actually succeed in decoding them before
attempting to do so. This will allow preservation of raw data even
when the raw data is corrupted relative to the specified filters.
For non-encrypted files, determinstic ID generation uses file contents
instead of timestamp and file name. At a small runtime cost, this
enables generation of the same /ID if the same inputs are converted in
the same way multiple times.
QPDFWriter was trying to make /Filter and /DecodeParms direct in all
cases, but there are some cases where /DecodeParms may refer to a
stream, which can't be direct. QPDFWriter doesn't actually need
/DecodeParms to be direct in that case because it won't be able to
filter the stream. Until we can handle this type of stream, just don't
make /Filter and /DecodeParms direct if we can't filter the stream
anyway.
Fixes #34
Fix problem: if the last object in the first part of a linearized file
had an offset that was below 65536 by less than the size of the hint
stream, the xref stream was invalid and the resulting file is not
usable.
Ideally, the library should never call assert outside of test code,
but it does in several places. For some cases where the assertion
might conceivably fail because of a problem with the input data,
replace assertions with exceptions so that they can be trapped by the
calling application. This commit surely misses some cases and
replaced some cases unnecessarily, but it should still be an
improvement.
4.2.0 was binary incompatible in spite of there being no deletions or
changes to any public methods. As such, we have to bump the ABI and
are fixing some API breakage while we're at it.
Previous 4.3.0 target is now 5.1.0.
Rework QPDFWriter to always track old object IDs and QPDFObjGen
instead of int, thus not discarding the generation number. Switch to
QPDF::getCompressibleObjGen() to properly handle the case of an old
object eligible for compression that has a generation of other than
zero.
Put a specific comment marker next to every piece of code that MSVC
gives warning 4996 for. This warning is generated for calls to
functions that Microsoft considers insecure or deprecated. This
change is in preparation for fixing all these cases even though none
of them are actually incorrect or insecure as used in qpdf. The
comment marker makes them easier to find so they can be fixed in
subsequent commits.
Original code was written before we could shallow copy objects, so all
the filtering was done by suppressing the output of certain keys and
replacing them with other keys. Now we can simplify the code greatly
by modifying shallow copies of dictionaries in place.
