flatten scalar references for unreferenced objects

git-svn-id: svn+q:///qpdf/trunk@946 71b93d88-0707-0410-a8cf-f5a4172ac649

4 files changed, 27 insertions, 7 deletions

diff --git a/libqpdf/QPDF_optimization.cc b/libqpdf/QPDF_optimization.cc
index e8d20fd5..872da859 100644
--- a/libqpdf/QPDF_optimization.cc
+++ b/libqpdf/QPDF_optimization.cc
@@ -69,18 +69,25 @@ QPDF::flattenScalarReferences()
     queue.push_back(this->trailer);
     std::set<ObjGen> visited;
 
+    // Add every object in the xref table to the queue.  This ensures
+    // that we flatten scalar references in unreferenced objects.
+    // This becomes important if we are preserving object streams in a
+    // file that has unreferenced objects in its object streams.  (See
+    // QPDF bug 2974522 at SourceForge.)
+    for (std::map<ObjGen, QPDFXRefEntry>::iterator iter =
+	     this->xref_table.begin();
+	 iter != this->xref_table.end(); ++iter)
+    {
+	ObjGen const& og = (*iter).first;
+	queue.push_back(getObjectByID(og.obj, og.gen));
+    }
+
     while (! queue.empty())
     {
 	QPDFObjectHandle node = queue.front();
 	queue.pop_front();
 	if (node.isIndirect())
 	{
-	    if (node.isScalar())
-	    {
-		throw std::logic_error(
-		    "INTERNAL ERROR:"
-		    " flattenScalarReferences landed at indirect scalar");
-	    }
 	    ObjGen og(node.getObjectID(), node.getGeneration());
 	    if (visited.count(og) > 0)
 	    {
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index 6d75a862..535d19d6 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -77,7 +77,7 @@ flush_tiff_cache();
 show_ntests();
 # ----------
 $td->notify("--- Miscellaneous Tests ---");
-$n_tests += 16;
+$n_tests += 18;
 
 $td->runtest("qpdf version",
 	     {$td->COMMAND => "qpdf --version"},
@@ -121,6 +121,19 @@ $td->runtest("show new xref stream",
 	      $td->EXIT_STATUS => 0},
 	     $td->NORMALIZE_NEWLINES);
 
+# Handle file with object stream containing an unreferenced object
+# that in turn contains an indirect scalar (bug 2974522).
+$td->runtest("unreferenced indirect scalar",
+	     {$td->COMMAND =>
+		  "qpdf --qdf --static-id --object-streams=preserve" .
+		  " unreferenced-indirect-scalar.pdf a.qdf"},
+	     {$td->STRING => "",
+	      $td->EXIT_STATUS => 0},
+	     $td->NORMALIZE_NEWLINES);
+$td->runtest("check output",
+	     {$td->FILE => "a.qdf"},
+	     {$td->FILE => "unreferenced-indirect-scalar.out"});
+
 # Min/Force version
 $td->runtest("set min version",
 	     {$td->COMMAND => "qpdf --min-version=1.6 good1.pdf a.pdf"},
diff --git a/qpdf/qtest/qpdf/unreferenced-indirect-scalar.out b/qpdf/qtest/qpdf/unreferenced-indirect-scalar.out
new file mode 100644
index 00000000..c1bf4a9d
--- /dev/null
+++ b/qpdf/qtest/qpdf/unreferenced-indirect-scalar.out
diff --git a/qpdf/qtest/qpdf/unreferenced-indirect-scalar.pdf b/qpdf/qtest/qpdf/unreferenced-indirect-scalar.pdf
new file mode 100644
index 00000000..e1be6311
--- /dev/null
+++ b/qpdf/qtest/qpdf/unreferenced-indirect-scalar.pdf