Support svgz in graphicfilter (import image to document)

Detect if input stream is gzip, if it is decompress and check the
decompressed stream if the content is svg.
When reading, decompress the whole svg content first, and then
store it internally.

Change-Id: Ie8b7e2b2f59a92d6420c38fd4a25637a6ee94425

vcl/source/filter/graphicfilter.cxx

@@ -25,6 +25,7 @@
 #include <ucbhelper/content.hxx>
 #include <cppuhelper/implbase1.hxx>
 #include <tools/urlobj.hxx>
+#include <tools/zcodec.hxx>
 #include <vcl/dibtools.hxx>
 #include <vcl/salctype.hxx>
 #include <vcl/pngread.hxx>
@@ -255,7 +256,7 @@ bool isPCT(SvStream& rStream, sal_uLong nStreamPos, sal_uLong nStreamLen)
 static bool ImpPeekGraphicFormat( SvStream& rStream, OUString& rFormatExtension, bool bTest )
 {
     sal_uInt16  i;
-    sal_uInt8    sFirstBytes[ 256 ];
+    sal_uInt8   sFirstBytes[ 256 ];
     sal_uLong   nFirstLong,nSecondLong;
     sal_uLong   nStreamPos = rStream.Tell();
 
@@ -645,89 +646,80 @@ static bool ImpPeekGraphicFormat( SvStream& rStream, OUString& rFormatExtension,
     //--------------------------- SVG ------------------------------------
     if( !bTest )
     {
-        // check for Xml
-        if( ImplSearchEntry( sFirstBytes, (sal_uInt8*)"<?xml", 256, 5 ) // is it xml
-            && ImplSearchEntry( sFirstBytes, (sal_uInt8*)"version", 256, 7 )) // does it have a version (required for xml)
-        {
-            bool bIsSvg(false);
-
-            // check for DOCTYPE svg combination
-            if( ImplSearchEntry( sFirstBytes, (sal_uInt8*)"DOCTYPE", 256, 7 ) // 'DOCTYPE' is there
-                && ImplSearchEntry( sFirstBytes, (sal_uInt8*)"svg", 256, 3 )) // 'svg' is there
-            {
-                bIsSvg = true;
-            }
+        sal_uInt8* pCheckArray = sFirstBytes;
+        sal_uLong nCheckSize = nStreamLen < 256 ? nStreamLen : 256;
 
-            // check for svg element in 1st 256 bytes
-            if(!bIsSvg && ImplSearchEntry( sFirstBytes, (sal_uInt8*)"<svg", 256, 4 )) // '<svg'
-            {
-                bIsSvg = true;
-            }
+        sal_uInt8 sExtendedOrDecompressedFirstBytes[2048];
+        sal_uLong nDecompressedSize = nCheckSize;
 
-            if(!bIsSvg)
-            {
-                // it's a xml, look for '<svg' in full file. Should not happen too
-                // often since the tests above will handle most cases, but can happen
-                // with Svg files containing big comment headers or Svg as the host
-                // language
-                const sal_uLong nSize((nStreamLen > 2048) ? 2048 : nStreamLen);
-                sal_uInt8* pBuf = new sal_uInt8[nSize];
+        bool bIsGZip(false);
 
-                rStream.Seek(nStreamPos);
-                rStream.Read(pBuf, nSize);
+        // check if it is gzipped -> svgz
+        if(sFirstBytes[0] == 0x1F && sFirstBytes[1] == 0x8B)
+        {
+            GZCodec aCodec;
+            rStream.Seek(nStreamPos);
+            aCodec.BeginCompression();
+            nDecompressedSize = aCodec.Read(rStream, sExtendedOrDecompressedFirstBytes, 2048);
+            nCheckSize = nDecompressedSize < 256 ? nDecompressedSize : 256;
+            aCodec.EndCompression();
+            pCheckArray = sExtendedOrDecompressedFirstBytes;
+        }
 
-                if(ImplSearchEntry(pBuf, (sal_uInt8*)"<svg", nSize, 4)) // '<svg'
-                {
-                    bIsSvg = true;
-                }
+        bool bIsSvg(false);
 
-                delete[] pBuf;
-            }
+        // check for Xml
+        // #119176# SVG files which have no xml header at all have shown up this is optional
+        if( ImplSearchEntry(pCheckArray, (sal_uInt8*)"<?xml", nCheckSize, 5 ) // is it xml
+            && ImplSearchEntry(pCheckArray, (sal_uInt8*)"version", nCheckSize, 7 )) // does it have a version (required for xml)
+        {
 
-            if(bIsSvg)
+            // check for DOCTYPE svg combination
+            if( ImplSearchEntry(pCheckArray, (sal_uInt8*)"DOCTYPE", nCheckSize, 7 ) // 'DOCTYPE' is there
+                && ImplSearchEntry(pCheckArray, (sal_uInt8*)"svg", nCheckSize, 3 )) // 'svg' is there
             {
-                rFormatExtension = "SVG";
-                return true;
+                bIsSvg = true;
             }
         }
-        else
+
+        // check for svg element in 1st 256 bytes
+        if(!bIsSvg && ImplSearchEntry(pCheckArray, (sal_uInt8*)"<svg", nCheckSize, 4 )) // '<svg'
+        {
+            bIsSvg = true;
+        }
+
+        // extended search for svg element
+        if(!bIsSvg)
         {
-            // #119176# SVG files which have no xml header at all have shown up,
-            // detect those, too
-            bool bIsSvg(false);
+            // it's a xml, look for '<svg' in full file. Should not happen too
+            // often since the tests above will handle most cases, but can happen
+            // with Svg files containing big comment headers or Svg as the host
+            // language
 
-            // check for svg element in 1st 256 bytes
-            if(ImplSearchEntry( sFirstBytes, (sal_uInt8*)"<svg", 256, 4 )) // '<svg'
+            pCheckArray = sExtendedOrDecompressedFirstBytes;
+
+            if(!bIsGZip)
             {
-                bIsSvg = true;
+                nCheckSize = nDecompressedSize < 2048 ? nDecompressedSize : 2048;
             }
-
-            if(!bIsSvg)
+            else
             {
-                // look for '<svg' in full file. Should not happen too
-                // often since the tests above will handle most cases, but can happen
-                // with SVG files containing big comment headers or SVG as the host
-                // language
-                const sal_uLong nSize((nStreamLen > 2048) ? 2048 : nStreamLen);
-                sal_uInt8* pBuf = new sal_uInt8[nSize];
-
+                nCheckSize = nStreamLen < 2048 ? nStreamLen : 2048;
                 rStream.Seek(nStreamPos);
-                rStream.Read(pBuf, nSize);
-
-                if(ImplSearchEntry(pBuf, (sal_uInt8*)"<svg", nSize, 4)) // '<svg'
-                {
-                    bIsSvg = true;
-                }
-
-                delete[] pBuf;
+                rStream.Read(sExtendedOrDecompressedFirstBytes, nCheckSize);
             }
 
-            if(bIsSvg)
+            if(ImplSearchEntry(pCheckArray, (sal_uInt8*)"<svg", nCheckSize, 4)) // '<svg'
             {
-                rFormatExtension = "SVG";
-                return true;
+                bIsSvg = true;
             }
         }
+
+        if(bIsSvg)
+        {
+            rFormatExtension = "SVG";
+            return true;
+        }
     }
     else if( rFormatExtension.startsWith( "SVG" ) )
     {
@@ -1521,27 +1513,53 @@ sal_uInt16 GraphicFilter::ImportGraphic( Graphic& rGraphic, const OUString& rPat
             if( rGraphic.GetContext() == (GraphicReader*) 1 )
                 rGraphic.SetContext( NULL );
 
-            const sal_uInt32 nStmPos(rIStream.Tell());
-            const sal_uInt32 nStmLen(rIStream.Seek(STREAM_SEEK_TO_END) - nStmPos);
+            const sal_uInt32 nStreamPosition(rIStream.Tell());
+            const sal_uInt32 nStreamLength(rIStream.Seek(STREAM_SEEK_TO_END) - nStreamPosition);
+
             bool bOkay(false);
 
-            if(nStmLen)
+            if(nStreamLength > 0)
             {
-                SvgDataArray aNewData(new sal_uInt8[nStmLen]);
+                std::vector<sal_uInt8> aTwoBytes(2);
+                rIStream.Seek(nStreamPosition);
+                rIStream.Read(&aTwoBytes[0], 2);
+                rIStream.Seek(nStreamPosition);
+                if(aTwoBytes[0] == 0x1F && aTwoBytes[1] == 0x8B)
+                {
+                    SvMemoryStream aMemStream;
+                    GZCodec aCodec;
+                    sal_uInt32 nMemoryLength;
 
-                rIStream.Seek(nStmPos);
-                rIStream.Read(aNewData.get(), nStmLen);
+                    aCodec.BeginCompression();
+                    nMemoryLength = aCodec.Decompress(rIStream, aMemStream);
+                    aCodec.EndCompression();
 
-                if(!rIStream.GetError())
+                    if(!rIStream.GetError() )
+                    {
+                        SvgDataArray aNewData(new sal_uInt8[nMemoryLength]);
+                        aMemStream.Seek(STREAM_SEEK_TO_BEGIN);
+                        aMemStream.Read(aNewData.get(), nMemoryLength);
+
+                        if(!aMemStream.GetError() )
+                        {
+                            SvgDataPtr aSvgDataPtr(new SvgData(aNewData, nMemoryLength, rPath));
+                            rGraphic = Graphic(aSvgDataPtr);
+                            bOkay = true;
+                        }
+                    }
+                }
+                else
                 {
-                    SvgDataPtr aSvgDataPtr(
-                        new SvgData(
-                            aNewData,
-                            nStmLen,
-                            rPath));
-
-                    rGraphic = Graphic(aSvgDataPtr);
-                    bOkay = true;
+                    SvgDataArray aNewData(new sal_uInt8[nStreamLength]);
+                    rIStream.Seek(nStreamPosition);
+                    rIStream.Read(aNewData.get(), nStreamLength);
+
+                    if(!rIStream.GetError())
+                    {
+                        SvgDataPtr aSvgDataPtr(new SvgData(aNewData, nStreamLength, rPath));
+                        rGraphic = Graphic(aSvgDataPtr);
+                        bOkay = true;
+                    }
                 }
             }