o Added a Clone() method to InterchangeObject and derivatives

   that allows making a descriptor copy that is not owned by
   any other strucure. The caller must arrange to delete the
   object pointer returned.

 o While implementing the above it became obvious that the
   reference-to-a-pointer-to-the-dictionary idiom that is used
   throughout the lower levels of the MXF library was the
   cause of much more grief than it was originally designed to
   prevent. This was made even more obvious when I replaced all
   of it with simple pointers, which revealed several shadow
   instances of m_Dict that were only reliable while the object
   that held them was valid.

1 files changed, 13 insertions, 13 deletions

diff --git a/src/AS_DCP_internal.h b/src/AS_DCP_internal.h
index 7162368..a86783e 100755
--- a/src/AS_DCP_internal.h
+++ b/src/AS_DCP_internal.h
@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2004-2018, John Hurst
+Copyright (c) 2004-2021, John Hurst
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -166,12 +166,12 @@ namespace ASDCP
   Result_t MD_to_PCM_ADesc(ASDCP::MXF::WaveAudioDescriptor* ADescObj, PCM::AudioDescriptor& ADesc);
 
   void     AddDmsCrypt(Partition& HeaderPart, SourcePackage& Package,
-		       WriterInfo& Descr, const UL& WrappingUL, const Dictionary*& Dict);
+		       WriterInfo& Descr, const UL& WrappingUL, const Dictionary *Dict);
 
   Result_t AddDmsTrackGenericPartUtf8Text(Kumu::FileWriter&, ASDCP::MXF::OP1aHeader&, SourcePackage&,
-					  ASDCP::MXF::RIP&, const Dictionary*&);
+					  ASDCP::MXF::RIP&, const Dictionary*);
   //
-  Result_t WriteGenericStreamPartition(Kumu::FileWriter&, ASDCP::MXF::OP1aHeader&, ASDCP::MXF::RIP&, const Dictionary*&,
+  Result_t WriteGenericStreamPartition(Kumu::FileWriter&, ASDCP::MXF::OP1aHeader&, ASDCP::MXF::RIP&, const Dictionary*,
 				       const ASDCP::FrameBuffer&, ASDCP::AESEncContext* = 0, ASDCP::HMACContext* = 0);
   
   Result_t Read_EKLV_Packet(Kumu::FileReader& File, const ASDCP::Dictionary& Dict,
@@ -216,7 +216,7 @@ namespace ASDCP
 	TrackFileReader();
 
       public:
-	const Dictionary*  m_Dict;
+	const Dictionary  *m_Dict;
 	Kumu::FileReader   m_File;
 	HeaderType         m_HeaderPart;
 	IndexAccessType    m_IndexAccess;
@@ -225,8 +225,8 @@ namespace ASDCP
 	ASDCP::FrameBuffer m_CtFrameBuf;
 	Kumu::fpos_t       m_LastPosition;
 
-      TrackFileReader(const Dictionary& d) :
-	m_HeaderPart(m_Dict), m_IndexAccess(m_Dict), m_RIP(m_Dict), m_Dict(&d)
+      TrackFileReader(const Dictionary *d) :
+	m_HeaderPart(d), m_IndexAccess(d), m_RIP(d), m_Dict(d)
 	  {
 	    default_md_object_init();
 	  }
@@ -496,7 +496,7 @@ namespace ASDCP
       template <class PackageT, class ClipT>
 	TrackSet<ClipT>
 	CreateTrackAndSequence(OP1aHeader& Header, PackageT& Package, const std::string TrackName,
-			       const MXF::Rational& clip_edit_rate, const UL& Definition, ui32_t TrackID, const Dictionary*& Dict)
+			       const MXF::Rational& clip_edit_rate, const UL& Definition, ui32_t TrackID, const Dictionary *Dict)
 	{
 	  TrackSet<ClipT> NewTrack;
 
@@ -519,7 +519,7 @@ namespace ASDCP
       template <class PackageT>
 	TrackSet<TimecodeComponent>
 	CreateTimecodeTrack(OP1aHeader& Header, PackageT& Package,
-			    const MXF::Rational& tc_edit_rate, ui32_t tc_frame_rate, ui64_t TCStart, const Dictionary*& Dict)
+			    const MXF::Rational& tc_edit_rate, ui32_t tc_frame_rate, ui64_t TCStart, const Dictionary *Dict)
 	{
 	  assert(Dict);
 	  UL TCUL(Dict->ul(MDD_TimecodeDataDef));
@@ -610,8 +610,8 @@ namespace ASDCP
 	typedef std::list<ui64_t*> DurationElementList_t;
 	DurationElementList_t m_DurationUpdateList;
 
-      TrackFileWriter(const Dictionary& d) :
-	m_Dict(&d), m_HeaderSize(0), m_HeaderPart(m_Dict), m_RIP(m_Dict),
+      TrackFileWriter(const Dictionary *d) :
+	m_Dict(d), m_HeaderSize(0), m_HeaderPart(m_Dict), m_RIP(m_Dict),
 	  m_MaterialPackage(0), m_FilePackage(0), m_ContentStorage(0),
 	  m_EssenceDescriptor(0), m_FramesWritten(0), m_StreamOffset(0)
 	  {
@@ -909,7 +909,7 @@ namespace ASDCP
     public:
       Partition m_BodyPart;
 
-      h__ASDCPReader(const Dictionary&);
+      h__ASDCPReader(const Dictionary*);
       virtual ~h__ASDCPReader();
 
       Result_t OpenMXFRead(const std::string& filename);
@@ -929,7 +929,7 @@ namespace ASDCP
       Partition          m_BodyPart;
       OPAtomIndexFooter  m_FooterPart;
 
-      h__ASDCPWriter(const Dictionary&);
+      h__ASDCPWriter(const Dictionary*);
       virtual ~h__ASDCPWriter();
 
       // all the above for a single source clip