tdf#103913 keep ".emf" file extension and mime type

in documents, don't change them to wmf and image/x-wmf
silently, resulting for example, dropping or rejecting
modified documents by firewall packet filtering.

Change-Id: I3b8634ae022c7c026b0ed4ebc345c1c3b3f96337
Reviewed-on: https://gerrit.libreoffice.org/56045Reviewed-by: László Németh <nemeth@numbertext.org>
Tested-by: László Németh <nemeth@numbertext.org>

include/vcl/gfxlink.hxx

@@ -111,6 +111,7 @@ public:
     void                SwapIn();
     bool                IsSwappedOut() const { return( bool(mpSwapOutData) ); }
 
+    bool                IsEMF() const; // WMF & EMF stored under the same type (NativeWmf)
 public:
 
     friend VCL_DLLPUBLIC SvStream&  WriteGfxLink( SvStream& rOStream, const GfxLink& rGfxLink );

svx/source/xml/xmlgrhlp.cxx

@@ -658,7 +658,12 @@ OUString SvXMLGraphicHelper::implSaveGraphic(css::uno::Reference<css::graphic::X
                 case GfxLinkType::NativeJpg: aExtension = ".jpg"; break;
                 case GfxLinkType::NativePng: aExtension = ".png"; break;
                 case GfxLinkType::NativeTif: aExtension = ".tif"; break;
-                case GfxLinkType::NativeWmf: aExtension = ".wmf"; break;
+                case GfxLinkType::NativeWmf:
+                    if (aGfxLink.IsEMF())
+                        aExtension = ".emf";
+                    else
+                        aExtension = ".wmf";
+                    break;
                 case GfxLinkType::NativeMet: aExtension = ".met"; break;
                 case GfxLinkType::NativePct: aExtension = ".pct"; break;
                 case GfxLinkType::NativeSvg:

sw/source/filter/ww8/rtfattributeoutput.cxx

@@ -3682,21 +3682,6 @@ void RtfAttributeOutput::FontPitchType(FontPitch ePitch) const
     m_rExport.OutULong(nVal);
 }
 
-static bool IsEMF(const sal_uInt8* pGraphicAry, unsigned long nSize)
-{
-    if (pGraphicAry && (nSize > 0x2c))
-    {
-        // check the magic number
-        if ((pGraphicAry[0x28] == 0x20) && (pGraphicAry[0x29] == 0x45)
-            && (pGraphicAry[0x2a] == 0x4d) && (pGraphicAry[0x2b] == 0x46))
-        {
-            //emf detected
-            return true;
-        }
-    }
-    return false;
-}
-
 static bool StripMetafileHeader(const sal_uInt8*& rpGraphicAry, unsigned long& rSize)
 {
     if (rpGraphicAry && (rSize > 0x22))
@@ -3938,8 +3923,8 @@ void RtfAttributeOutput::FlyFrameGraphic(const SwFlyFrameFormat* pFlyFrameFormat
                 pBLIPType = OOO_STRING_SVTOOLS_RTF_PNGBLIP;
                 break;
             case GfxLinkType::NativeWmf:
-                pBLIPType = IsEMF(pGraphicAry, nSize) ? OOO_STRING_SVTOOLS_RTF_EMFBLIP
-                                                      : OOO_STRING_SVTOOLS_RTF_WMETAFILE;
+                pBLIPType = aGraphicLink.IsEMF() ? OOO_STRING_SVTOOLS_RTF_EMFBLIP
+                                                 : OOO_STRING_SVTOOLS_RTF_WMETAFILE;
                 break;
             case GfxLinkType::NativeGif:
                 // GIF is not supported by RTF, but we override default conversion to WMF, PNG seems fits better here.

vcl/source/gdi/gfxlink.cxx

@@ -286,4 +286,20 @@ std::shared_ptr<sal_uInt8> GfxLink::GetSwapInData() const
     return pData;
 }
 
+bool GfxLink::IsEMF() const
+{
+    const sal_uInt8* pGraphicAry = GetData();
+    if ((GetType() == GfxLinkType::NativeWmf) && pGraphicAry && (GetDataSize() > 0x2c))
+    {
+        // check the magic number
+        if ((pGraphicAry[0x28] == 0x20) && (pGraphicAry[0x29] == 0x45)
+            && (pGraphicAry[0x2a] == 0x4d) && (pGraphicAry[0x2b] == 0x46))
+        {
+            //emf detected
+            return true;
+        }
+    }
+    return false;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */