Revert "Simplify GfxLink using std::shared_ptr to clarify ownership"

This reverts commit d64431ac, which caused ASan
to complain about "alloc-dealloc-mismatch (operator new [] vs operator delete)"
(while e.g. building Gallery_arrows), as GfxLink::mpSwpInData is a
std::shared_ptr<sal_uInt8> holding a pointer to an array of sal_uInt8.

include/vcl/gfxlink.hxx

@@ -25,10 +25,56 @@
 #include <tools/solar.h>
 #include <vcl/dllapi.h>
 #include <vcl/mapmod.hxx>
-#include <memory>
 
 class SvStream;
 
+
+struct ImpBuffer
+{
+    sal_uLong       mnRefCount;
+    sal_uInt8*      mpBuffer;
+
+                ImpBuffer( sal_uInt8* pBuf ) { mnRefCount = 1UL; mpBuffer = pBuf; }
+
+                ~ImpBuffer() { delete[] mpBuffer; }
+};
+
+
+struct ImpSwap
+{
+    OUString   maURL;
+    sal_uLong           mnDataSize;
+    sal_uLong           mnRefCount;
+
+                    ImpSwap( sal_uInt8* pData, sal_uLong nDataSize );
+                    ~ImpSwap();
+
+    sal_uInt8*          GetData() const;
+
+    bool            IsSwapped() const { return maURL.getLength() > 0; }
+
+    void            WriteTo( SvStream& rOStm ) const;
+};
+
+
+struct ImpGfxLink
+{
+    MapMode         maPrefMapMode;
+    Size            maPrefSize;
+    bool            mbPrefMapModeValid;
+    bool            mbPrefSizeValid;
+
+    ImpGfxLink() :
+        maPrefMapMode(),
+        maPrefSize(),
+        mbPrefMapModeValid( false ),
+        mbPrefSizeValid( false )
+    {}
+};
+
+//#endif // __PRIVATE
+
+
 enum GfxLinkType
 {
     GFX_LINK_TYPE_NONE          = 0,
@@ -42,6 +88,7 @@ enum GfxLinkType
     GFX_LINK_TYPE_NATIVE_PCT    = 8,    // Don't forget to update the following defines
     GFX_LINK_TYPE_NATIVE_SVG    = 9,    // Don't forget to update the following defines
     GFX_LINK_TYPE_NATIVE_MOV    = 10,   // Don't forget to update the following defines
+    // #i15508# added BMP type support
     GFX_LINK_TYPE_NATIVE_BMP    = 11,   // Don't forget to update the following defines
     GFX_LINK_TYPE_USER          = 0xffff
 };
@@ -49,58 +96,49 @@ enum GfxLinkType
 #define GFX_LINK_FIRST_NATIVE_ID    GFX_LINK_TYPE_NATIVE_GIF
 #define GFX_LINK_LAST_NATIVE_ID     GFX_LINK_TYPE_NATIVE_BMP
 
+
+struct ImpBuffer;
+struct ImpSwap;
+struct ImpGfxLink;
 class Graphic;
 
 class VCL_DLLPUBLIC GfxLink
 {
 private:
 
-    struct SwapOutData
-    {
-        SwapOutData(const OUString &aURL);
-        ~SwapOutData();
+    GfxLinkType         meType;
+    ImpBuffer*          mpBuf;
+    ImpSwap*            mpSwap;
+    sal_uInt32          mnBufSize;
+    sal_uInt32          mnUserId;
+    ImpGfxLink*         mpImpData;
 
-        OUString maURL; // File is removed in the destructor
+    SAL_DLLPRIVATE void ImplCopy( const GfxLink& rGfxLink );
 
-    };
-
-    GfxLinkType     meType = GFX_LINK_TYPE_NONE;
-    sal_uInt32      mnUserId = 0;
-
-    std::shared_ptr<sal_uInt8> mpSwapInData;
-    std::shared_ptr<SwapOutData> mpSwapOutData;
-
-    sal_uInt32      mnSwapInDataSize = 0;
-    MapMode         maPrefMapMode;
-    Size            maPrefSize;
-    bool            mbPrefMapModeValid = false;
-    bool            mbPrefSizeValid = false;
-
-    SAL_DLLPRIVATE std::shared_ptr<sal_uInt8> GetSwapInData() const;
 public:
                         GfxLink();
-
-                        // pBuff = The Graphic data. This class takes ownership of this
+                        GfxLink( const GfxLink& );
                         GfxLink( sal_uInt8* pBuf, sal_uInt32 nBufSize, GfxLinkType nType );
                         ~GfxLink();
 
-    bool                IsEqual( const GfxLink& ) const;
+    GfxLink&            operator=( const GfxLink& );
+    bool            IsEqual( const GfxLink& ) const;
 
     GfxLinkType         GetType() const { return meType;}
 
     void                SetUserId( sal_uInt32 nUserId ) { mnUserId = nUserId; }
     sal_uInt32          GetUserId() const { return mnUserId; }
 
-    sal_uInt32          GetDataSize() const { return mnSwapInDataSize;}
+    sal_uInt32          GetDataSize() const { return mnBufSize;}
     const sal_uInt8*    GetData() const;
 
-    const Size&         GetPrefSize() const { return maPrefSize;}
+    const Size&         GetPrefSize() const { return mpImpData->maPrefSize;}
     void                SetPrefSize( const Size& rPrefSize );
-    bool                IsPrefSizeValid() { return mbPrefSizeValid;}
+    bool                IsPrefSizeValid() { return mpImpData->mbPrefSizeValid;}
 
-    const MapMode&      GetPrefMapMode() const { return maPrefMapMode;}
+    const MapMode&      GetPrefMapMode() const { return mpImpData->maPrefMapMode;}
     void                SetPrefMapMode( const MapMode& rPrefMapMode );
-    bool                IsPrefMapModeValid() { return mbPrefMapModeValid;}
+    bool                IsPrefMapModeValid() { return mpImpData->mbPrefMapModeValid;}
 
     bool                IsNative() const;
 
@@ -110,7 +148,7 @@ public:
 
     void                SwapOut();
     void                SwapIn();
-    bool                IsSwappedOut() const { return( bool(mpSwapOutData) ); }
+    bool                IsSwappedOut() const { return( mpSwap != nullptr ); }
 
 public: