Implement QPDFObjectHandle::parse

Move object parsing code from QPDF to QPDFObjectHandle and
parameterize the parts of it that are specific to a QPDF object.
Provide a version that can't handle indirect objects and that can be
called on an arbitrary string.

A side effect of this change is that the offset used when reporting
invalid stream length has changed, but since the new value seems like
a better value than the old one, the test suite has been updated
rather than making the code backward compatible.  This only effects
the offset reported for invalid streams that lack /Length or have an
invalid /Length key.

Updated some test code and exmaples to use QPDFObjectHandle::parse.

Supporting changes include adding a BufferInputSource constructor that
takes a string.

1 files changed, 2 insertions, 0 deletions

diff --git a/include/qpdf/BufferInputSource.hh b/include/qpdf/BufferInputSource.hh
index 63c14def..48f6e3ac 100644
--- a/include/qpdf/BufferInputSource.hh
+++ b/include/qpdf/BufferInputSource.hh
@@ -9,6 +9,8 @@ class BufferInputSource: public InputSource
   public:
     BufferInputSource(std::string const& description, Buffer* buf,
                       bool own_memory = false);
+    BufferInputSource(std::string const& description,
+                      std::string const& contents);
     virtual ~BufferInputSource();
     virtual qpdf_offset_t findAndSkipNextEOL();
     virtual std::string const& getName() const;