xmlsecurity PDF sign: use a predictor when compressing the xref stream

With this our xref stream output is close enough to Acrobat so that the
existing signature verifier runs without any problems.

Change-Id: I6eca7966890365759c269b465e4bf4d86d335219

1 files changed, 16 insertions, 0 deletions

diff --git a/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx b/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx
index a6c764d6e3dd..7a8df3f4236e 100644
--- a/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx
+++ b/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx
@@ -58,6 +58,8 @@ public:
     void testPDF14Adobe();
     /// Test a PDF 1.6 document, signed by Adobe.
     void testPDF16Adobe();
+    /// Test adding a signature to a PDF 1.6 document.
+    void testPDF16Add();
     /// Test a PDF 1.4 document, signed by LO on Windows.
     void testPDF14LOWin();
 
@@ -68,6 +70,7 @@ public:
     CPPUNIT_TEST(testPDFRemoveAll);
     CPPUNIT_TEST(testPDF14Adobe);
     CPPUNIT_TEST(testPDF16Adobe);
+    CPPUNIT_TEST(testPDF16Add);
     CPPUNIT_TEST(testPDF14LOWin);
     CPPUNIT_TEST_SUITE_END();
 };
@@ -270,6 +273,19 @@ void PDFSigningTest::testPDF16Adobe()
     verify(m_directories.getURLFromSrc(DATA_DIRECTORY) + "pdf16adobe.pdf", 1);
 }
 
+void PDFSigningTest::testPDF16Add()
+{
+    // Contains PDF 1.6 features, make sure we can add a signature using that
+    // markup correctly.
+    OUString aSourceDir = m_directories.getURLFromSrc(DATA_DIRECTORY);
+    OUString aInURL = aSourceDir + "pdf16adobe.pdf";
+    OUString aTargetDir = m_directories.getURLFromWorkdir("/CppunitTest/xmlsecurity_pdfsigning.test.user/");
+    OUString aOutURL = aTargetDir + "add.pdf";
+    // This failed: verification broke as incorrect xref stream was written as
+    // part of the new signature.
+    sign(aInURL, aOutURL, 1);
+}
+
 void PDFSigningTest::testPDF14LOWin()
 {
     // mscrypto used SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION as a digest