This makes all integer type conversions that have potential data loss
explicit with calls that do range checks and raise an exception. After
this commit, qpdf builds with no warnings when -Wsign-conversion
-Wconversion is used with gcc or clang or when -W3 -Wd4800 is used
with MSVC. This significantly reduces the likelihood of potential
crashes from bogus integer values.
There are some parts of the code that take int when they should take
size_t or an offset. Such places would make qpdf not support files
with more than 2^31 of something that usually wouldn't be so large. In
the event that such a file shows up and is valid, at least qpdf would
raise an error in the right spot so the issue could be legitimately
addressed rather than failing in some weird way because of a silent
overflow condition.
Bounding box X coordinates could be truncated, causing them to be off
by a fraction of a point. This was most likely not visible, but it was
still wrong.
On read, ignore /DecodeParms when empty list; on write, delete it.
Some files have been found that include an empty list for
/DecodeParms, but this is not technically compliant with the spec, and
the only sensible interpretation is to treat it as if there are no
decode parameters.
* [bcc32 Error] QPDF.cc(375): E2268 Call to undefined function 'atof'
Full parser context
QPDF.cc(358): parsing: void QPDF::parse(const char *)
* [bcc32 Error] QPDFTokenizer.cc(183): E2268 Call to undefined function 'strtol'
Full parser context
QPDFTokenizer.cc(163): parsing: void QPDFTokenizer::resolveLiteral()
* [bcc32 Error] pdf-split-pages.cc(52): E2268 Call to undefined function 'exit'
Full parser context
pdf-split-pages.cc(50): parsing: void usage()
* PR #295: Including "cstdlib" should be replaced with "stdlib.h" to be more consistent. At the same time I changed the order of the surrounding includes to reflect alphabetical order, because at some files this already have been the case.
We've actually seen a PDF file in the wild that contained EI
surrounded by delimiters inside the image data, which confused qpdf's
naive code. This significantly improves EI detection.
Add a version of expectInlineImage that takes an input source and
searches for EI. This is in preparation for improving the way EI is
found. This commit just refactors the code without changing the
functionality and adds tests to make sure the old and new code behave
identically.
When linearizing a file or getting the list of all pages in a file,
detect if the pages tree contains a duplicated page object and, if so,
shallow copy it. This makes it possible to have a one to one mapping
of page positions to page objects.
When generating appearance streams for variable text annotations,
properly handle the cases of there being no appearance dictionary, no
appearance stream, or an appearance stream with no BMC..EMC marker.
With the exception of form field annotations when /NeedAppearances is
true, remove annotations that don't have appearance streams when
flattening. There is no reason to keep these when flattening since
they are invisible. This may include unchecked checkboxes, unshown
popup windows, etc.
Setting encryption permissions for R >= 3 set permission bits in
groups corresponding to menu options in Acrobat 5. The new API allows
the bits to be set individually.
Explicitly abandon removal of unreferenced resources if there are any
lexical errors in the page's contents. This case always generated a
warning, but it now also prevents removal of unreferenced resources,
this strongly decreasing the likelihood of data loss.
