Improve: Avoid overwriting bytes in scratch buffer
Improve: Avoid overwriting bytes in scratch buffer

There was one corner case which was not considered correctly in
the orignial fix de1be2a37876cb89713aa4d9b5fb23e4d8942d5f
Avoid overwriting bytes in scratch buffer. This one corrects
it. Initial internal tests suceeded on this one and failed on
the previous version.

ferseiti/genwqe-user,tblume/genwqe-user,ibm-genwqe/genwqe-user,ibm-genwqe/genwqe-user,ibm-genwqe/genwqe-user,tblume/genwqe-user,ferseiti/genwqe-user