restore the stream position in wxImageHandler itself instead of forcing all

derived classes to do it themselves


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15642 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/image.h

@@ -53,7 +53,7 @@ public:
 
     virtual int GetImageCount( wxInputStream& stream );
 
-    bool CanRead( wxInputStream& stream ) { return DoCanRead(stream); }
+    bool CanRead( wxInputStream& stream ) { return CallDoCanRead(stream); }
     bool CanRead( const wxString& name );
 #endif // wxUSE_STREAMS
 
@@ -71,6 +71,9 @@ protected:
     virtual bool DoCanRead( wxInputStream& stream ) = 0;
 #endif // wxUSE_STREAMS
 
+    // save the stream position, call DoCanRead() and restore the position
+    bool CallDoCanRead(wxInputStream& stream);
+
     wxString  m_name;
     wxString  m_extension;
     wxString  m_mime;