OpenSystemsDevelopment / qpdf

Fix QPDF::recoverStreamLength

Tidy QPDF_Stream

Replace some std::shared_ptr parameters with reference parameters

1. Make class final
2. Pass og parameter by value
3. Properly initialize qpdf and og

Also, tweak QPDF::replaceObject to allow stream replacement without
violating the requirement that streams must always be indirect objects.

Also, remove QPDF::reserveStream as it does not do what the name implies
and having this as a separate methods does not aid code readability.

Given that the PDF spec requires the xref table to contain entries for all
object ids <= the maximum id present in a PDF document, max_size is a
qpdf implementation limitation for legitimate object ids.

Refactor Pl_QPDFTokenizer

Ensure the the recovered stream end is not part of a different object.

Test file is bad24.pdf with stream 4 'endstream' corrupted.

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).

Buffer output locally.
Add qpdf_fuzzer test case.

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

Remove unnecessary use of shared pointers and avoid unnecessary string
creation.

Avoid writing each space char individually.

Wrap-around is intentional and generates false positives

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.