xmlsecurity PDF verify: tolerate missing %%EOF in incremental updates

This is broken, but work it around to avoid an infinite loop.

Change-Id: I132a3c19cfe53e6166bfc1a881d1bfa5071f85d4
Reviewed-on: https://gerrit.libreoffice.org/31471
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

1 files changed, 8 insertions, 4 deletions

diff --git a/xmlsecurity/source/pdfio/pdfdocument.cxx b/xmlsecurity/source/pdfio/pdfdocument.cxx
index e3e89a0750ee..86aff1eb3f5a 100644
--- a/xmlsecurity/source/pdfio/pdfdocument.cxx
+++ b/xmlsecurity/source/pdfio/pdfdocument.cxx
@@ -1228,8 +1228,12 @@ bool PDFDocument::Tokenize(SvStream& rStream, TokenizeMode eMode, std::vector< s
                 }
                 else if (aKeyword == "trailer")
                 {
-                    m_pTrailer = new PDFTrailerElement(*this);
-                    rElements.push_back(std::unique_ptr<PDFElement>(m_pTrailer));
+                    auto pTrailer = new PDFTrailerElement(*this);
+                    // When reading till the first EOF token only, remember
+                    // just the first trailer token.
+                    if (eMode != TokenizeMode::EOF_TOKEN || !m_pTrailer)
+                        m_pTrailer = pTrailer;
+                    rElements.push_back(std::unique_ptr<PDFElement>(pTrailer));
                 }
                 else if (aKeyword == "startxref")
                 {
@@ -1680,9 +1684,9 @@ void PDFDocument::ReadXRef(SvStream& rStream)
             return;
         }
 
-        if (aNumberOfEntries.GetValue() <= 0)
+        if (aNumberOfEntries.GetValue() < 0)
         {
-            SAL_WARN("xmlsecurity.pdfio", "PDFDocument::ReadXRef: expected one or more entries");
+            SAL_WARN("xmlsecurity.pdfio", "PDFDocument::ReadXRef: expected zero or more entries");
             return;
         }