emfplus: Corrected ReadWindowMetafile

There are two places which do hand over not a
complete SvStream staring at pos zero, but pass
a seek position indirectly in that stream. Thus
this needs to be used. There is one usage in sc
that copies the data to a MemStream to avoid that,
so this hints that this 'trap/feature' was not
known to everyone using it

Change-Id: I94139b86c8bdd82879124c574bc3014e02d9ab5f
Reviewed-on: https://gerrit.libreoffice.org/41399
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>

1 files changed, 17 insertions, 4 deletions

diff --git a/vcl/source/filter/wmf/wmf.cxx b/vcl/source/filter/wmf/wmf.cxx
index fe9a9f4429ca..ac56c74810f4 100644
--- a/vcl/source/filter/wmf/wmf.cxx
+++ b/vcl/source/filter/wmf/wmf.cxx
@@ -25,12 +25,25 @@
 
 bool ReadWindowMetafile( SvStream& rStream, GDIMetaFile& rMTF )
 {
-    // Use new method to import Metafile. First, read binary data to mem array
-    const sal_uInt32 nStreamLength(rStream.Seek(STREAM_SEEK_TO_END));
+    // tdf#111484 Use new method to import Metafile. Take curent StreamPos
+    // into account (used by SwWW8ImplReader::ReadGrafFile and by
+    // SwWw6ReadMetaStream, so do *not* ignore. OTOH XclImpDrawing::ReadWmf
+    // is nice enough to copy to an own MemStream to avoid that indirect
+    // parameter passing...)
+    const sal_uInt32 nStreamStart(rStream.Tell());
+    const sal_uInt32 nStreamEnd(rStream.Seek(STREAM_SEEK_TO_END));
+
+    if (nStreamStart >= nStreamEnd)
+    {
+        return false;
+    }
+
+    // Read binary data to mem array
+    const sal_uInt32 nStreamLength(nStreamEnd - nStreamStart);
     VectorGraphicDataArray aNewData(nStreamLength);
-    rStream.Seek(0);
+    rStream.Seek(nStreamStart);
     rStream.ReadBytes(aNewData.begin(), nStreamLength);
-    rStream.Seek(0);
+    rStream.Seek(nStreamStart);
 
     if (rStream.good())
     {