From 06b818dcd39b5aeaeeee5c247483633a02a0222e Mon Sep 17 00:00:00 2001
From: Masamichi Hosoda <trueroad@trueroad.jp>
Date: Fri, 27 Sep 2019 21:00:30 +0900
Subject: [PATCH] Exclude signature dictionary from compressible objects

---
 libqpdf/QPDF.cc      | 8 +++++++-
 qpdf/qtest/qpdf.test | 4 ++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index c546fbe..6c0c700 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -2673,7 +2673,13 @@ QPDF::getCompressibleObjGens()
 	    {
 		QTC::TC("qpdf", "QPDF exclude encryption dictionary");
 	    }
-	    else if (! obj.isStream())
+	    else if ((! obj.isStream()) &&
+		     (! (obj.isDictionary() &&
+                         obj.hasKey("/ByteRange") &&
+                         obj.hasKey("/Contents") &&
+                         obj.hasKey("/Type") &&
+                         obj.getKey("/Type").isName() &&
+                         obj.getKey("/Type").getName() == "/Sig")))
 	    {
 		result.push_back(og);
 	    }
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index 9fdf9ba..d5caa9a 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -3998,9 +3998,9 @@ $td->runtest("fix-qdf with big object stream", # > 255 objects in a stream
 show_ntests();
 # ----------
 $td->notify("--- Signature Dictionary ---");
-$n_tests += 4;
+$n_tests += 6;
 
-foreach my $i (qw(preserve disable))
+foreach my $i (qw(preserve disable generate))
 {
     $td->runtest("sig dict contents hex (object-streams=$i)",
                  {$td->COMMAND =>
--
libgit2 0.21.4