tdf#114304 break rather than return false on dodgy record length

Change-Id: I1bc8c400147beb8688ed3afd7402b3d3f68a4a3a
Reviewed-on: https://gerrit.libreoffice.org/46043Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

filter/source/msfilter/msdffimp.cxx

@@ -6202,7 +6202,10 @@ bool SvxMSDffManager::GetShapeContainerData( SvStream& rSt,
         else
         {
             if (!checkSeek(rSt, rSt.Tell() + nLength))
-                return false;
+            {
+                SAL_WARN("filter.ms", "remaining record longer than available data, ppt or parser is wrong");
+                break;
+            }
             nReadSpCont += nLength;
         }
     }