OpenSystemsDevelopment / qpdf

ClosedFileInputSource is an input source that keeps the file closed
when not reading it.

It's not really a shallow copy. It just doesn't cross indirect object
boundaries. The old implementation had a bug that would cause multiple
shallow copies of the same object to share memory, which was not the
intention.

This is the beginning of higher-level API support using helper
classes. The goal is to be able to add more helpers without continuing
to pollute QPDF's and QPDFObjectHandle's public interfaces.

Provide a convenient way of accessing rectangles.

Remove calls to assertPageObject(). All cases in the library that
called assertPageObject() work fine if you don't call
assertPageObject() because nothing assumes anything that was being
checked by that call. Removing the calls enables more files to be
successfully processed.

The QPDF_String::getUTF8Val() method was not treating strings that
weren't explicitly Unicode as PDF Doc Encoded. This only affects
characters in the range 0x80 through 0xa0.

Give objects descriptions and context so it is possible to issue
warnings instead of fatal errors for attempts to access objects of the
wrong type.

As in other cases, this is to enable adding new member variables in
the future without breaking ABI compatibility.

Expose Pl_QPDFTokenizer, and have it do more of the work of managing
the token filter's pipeline.

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.

Remove a redundant method that was equal to another one with
additional arguments. This breaks binary compatibility, but there are
other ABI breaking changes in the upcoming release, so now is the time
to do it.

This is for protection against future ABI breaking changes.

Significant enhancements to the lexer to improve EOF handling and to
support comments and spaces as tokens. Various other minor issues were
fixed as well.

This is useful only for debugging the linearization code.

Add options to enable the raw encryption key to be directly shown or
specified. Thanks to Didier Stevens <didier.stevens@gmail.com> for the
idea and contribution of one implementation of this idea.

The Apache License version 2.0 is now the primary license for qpdf.
However, users may, at their option, continue to use Artistic version
2.0.

Tweak the message so that we inform the user that we are mitigating
data loss.