Comment 5 for bug 179738

For reference, adding some info from my e-mail message of 2010-03-24:

"[...] the first cond is strange, since add-to-list can never evaluate to nil: even if both the list-variable and the element are nil, then add-to-list will still return "(nil)" which is non-nil (i.e. it doesn't return the empty list, but a list with one element that is nil). So the first condition will always be true, and the remaining conditions cannot be reached."

I have eliminated these "add-to-list" conditions now.