avoid PDF export crash when ReadWithPossibleFixup falls back to Pdfium

Unfortunately, I failed to create a clean-room example,
even when I pasted some binary garbage at the end of the file.
Somehow I was getting a sanitized version from getAsStream.

In any case, this prevents crashing with the two examples I have,
although there are still significant problems somewhere
because the export just results in empty pages...

The problem is that reading again with the Pdfium-fixed version
gets mixed in with the original read results,
and things get pretty garbled.
Probably m_rElements and everything needs to be cleared
before tokenizing the fixup-version.

Change-Id: I01daefa23b8f92e2849d71bca269ba2b476199da
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/174648
Reviewed-by: Justin Luth <jluth@mail.com>
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
(cherry picked from commit 636e703722c1a36b4078de932b5a44855145c18a)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/174663
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/vcl/source/filter/ipdf/pdfdocument.cxx b/vcl/source/filter/ipdf/pdfdocument.cxx
index dac68d5344af..b5fbc757da57 100644
--- a/vcl/source/filter/ipdf/pdfdocument.cxx
+++ b/vcl/source/filter/ipdf/pdfdocument.cxx
@@ -1427,6 +1427,7 @@ bool PDFDocument::Read(SvStream& rStream)
             nStartXRef = pPrev->GetValue();
 
         // Reset state, except the edit buffer.
+        m_aOffsetTrailers.clear(); // contents are lifecycle managed by m_aElements
         m_aElements.clear();
         m_aOffsetObjects.clear();
         m_aIDObjects.clear();