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, 12 insertions, 0 deletions

diff --git a/libqpdf/BufferInputSource.cc b/libqpdf/BufferInputSource.cc
index 6909dce2..03439955 100644
--- a/libqpdf/BufferInputSource.cc
+++ b/libqpdf/BufferInputSource.cc
@@ -11,6 +11,18 @@ BufferInputSource::BufferInputSource(std::string const& description,
 {
 }
 
+BufferInputSource::BufferInputSource(std::string const& description,
+                                     std::string const& contents) :
+    own_memory(true),
+    description(description),
+    buf(0),
+    cur_offset(0)
+{
+    this->buf = new Buffer(contents.length());
+    unsigned char* bp = buf->getBuffer();
+    memcpy(bp, (char*)contents.c_str(), contents.length());
+}
+
 BufferInputSource::~BufferInputSource()
 {
     if (own_memory)