Use wxFS_SEEKABLE when opening images since some image handlers need seeking.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42513 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/winpars.cpp

@@ -332,7 +332,11 @@ wxFSFile *wxHtmlWinParser::OpenURL(wxHtmlURLType type,
     if ( status == wxHTML_BLOCK )
         return NULL;
 
-    return GetFS()->OpenFile(myurl);
+    int flags = wxFS_READ;
+    if (type == wxHTML_URL_IMAGE)
+        flags |= wxFS_SEEKABLE;
+
+    return GetFS()->OpenFile(myurl, flags);
 }
 
 void wxHtmlWinParser::AddText(const wxChar* txt)