OpenSystemsDevelopment / qpdf

Create unresolved objects only for objects in the xref table (except during
parsing of the xref table). Do not add indirect nulls into the the object
cache as the result of a cache miss during a call to getObject except
during parsing or creation/updating from JSON. To support this behaviour,
add new private methods getObjectForParser and getObjectForJSON.

As a result of this change, dangling references are treated as direct nulls
rather than indirect nulls.

Prepare for treating indirect references differently depending on whether
we are parsing a PDF file (in which case reference to objects not in the
xref table are null even if they are in the object cache) or whether parse
from user code (in which case an indirect reference can refer to a user
created object).

Fix writing reals with trailing '.' as JSON (fixes #1261)

libtests: include cstdint for GCC 15

GCC 15 starts to no longer include this by default, requiring it to be
explicitly included.

Error message:
libtests/cxx11.cc:75:16: error: ‘uint8_t’ was not declared in this scope
   75 |     check_size<uint8_t>(1, false);
      |                ^~~~~~~
libtests/cxx11.cc:10:1: note: ‘uint8_t’ is defined in header ‘<cstdint>’; this is probably fixable by adding ‘#include <cstdint>’
    9 | #include <regex>
  +++ |+#include <cstdint>
   10 | #include <type_traits>

Signed-off-by: Christopher Fore <csfore@posteo.net>

Adjust fuzzer memory limits and refactor Pl_RunLength::decode

Buffer output locally.
Add qpdf_fuzzer test case.

Also, add additional qpdf_fuzzer test case.

In QPDFWriter::willFilterStream remember unfilterable streams

Refactor xref reconstruction

Avoid unnecessary rescanning of lines and repositioning of input file.
Limit max size of tokens.

Adjust qpdf_fuzzer warnings limit

Mark intentional unsigned integer wrapping in MD5_native::transform and adjust fuzzer memory limits

Wrap-around is intentional and generates false positives

Update TODO.md

Also, remove closed fuzz cases.

In FUTURE make various QPDFObjectHandle methods const

Adjust fuzzer warning and memory limits

Fix QPDFOutlineDocumentHelper::resolveNamedDest  (fixes #1238)

Throw damagedFile if max_warnings is exceeded. Change qpdf_fuzzer warnings limit to
limit to 500.

Tighten page tree checks

Add further sanity checks to QPDF::reconstruct_xref

Handle case where named destination is a dictionary with /D entry.

Test case is hand-edited outlines-with-old-root-dests.pdf with modified
object 107.

Run getAllPages as sanity check and throw an exception if too many
warnings are generated or no pages are found.

Add further sanity check to QPDF::reconstruct_xref

Try a  limit of 50MB. For very large limits processing time before
damage is encountered may exceed oss-fuzz limits.
Add further test cases.