Comment 8 for bug 1878984

I don't have a fix for this right now, but I have identified the issue in the code. Commit 23293c7f reworked how the replace rules were processed to allow, say, subfield 0 to remain at the end of the field. However, it now requires that the "target" record (the new record in the case of a preserve rule) have the named field in order for the value from the "source" (old record) to be moved over.