Add Pl_Concatenate filter

include/qpdf/Pl_Concatenate.hh

@@ -0,0 +1,32 @@
+#ifndef __PL_CONCATENATE_HH__
+#define __PL_CONCATENATE_HH__
+
+// This pipeline will drop all regular finished calls rather than
+// passing them onto next.  To finish downstream streams, call
+// manualFinish.  This makes it possible to pipe multiple streams
+// (e.g. with QPDFObjectHandle::pipeStreamData) to a downstream like
+// Pl_Flate that can't handle multiple calls to finish().
+
+#include <qpdf/Pipeline.hh>
+
+class Pl_Concatenate: public Pipeline
+{
+  public:
+    QPDF_DLL
+    Pl_Concatenate(char const* identifier, Pipeline* next);
+    QPDF_DLL
+    virtual ~Pl_Concatenate();
+
+    QPDF_DLL
+    virtual void write(unsigned char* data, size_t len);
+
+    QPDF_DLL
+    virtual void finish();
+
+    // At the very end, call manualFinish actually finish the rest of
+    // the pipeline.
+    QPDF_DLL
+    void manualFinish();
+};
+
+#endif // __PL_CONCATENATE_HH__

libqpdf/Pl_Concatenate.cc

@@ -0,0 +1,28 @@
+#include <qpdf/Pl_Concatenate.hh>
+
+Pl_Concatenate::Pl_Concatenate(char const* identifier, Pipeline* next) :
+    Pipeline(identifier, next)
+{
+}
+
+Pl_Concatenate::~Pl_Concatenate()
+{
+}
+
+void
+Pl_Concatenate::write(unsigned char* data, size_t len)
+{
+    getNext()->write(data, len);
+}
+
+void
+Pl_Concatenate::finish()
+{
+}
+
+void
+Pl_Concatenate::manualFinish()
+{
+    getNext()->finish();
+}
+

libqpdf/build.mk

@@ -15,6 +15,7 @@ SRCS_libqpdf = \
 	libqpdf/Pl_ASCII85Decoder.cc \
 	libqpdf/Pl_ASCIIHexDecoder.cc \
 	libqpdf/Pl_Buffer.cc \
+	libqpdf/Pl_Concatenate.cc \
 	libqpdf/Pl_Count.cc \
 	libqpdf/Pl_Discard.cc \
 	libqpdf/Pl_Flate.cc \