improve formatting

Change-Id: Id652ff18023965cb2bcc7c10520f95a51e8ac15d
handle all fill cases correctly, fdo#86754

That special case only works if the whole source range contains formula
cells. For now we just limit it to the special case of a single source
cell.

Change-Id: I71ccfde06edd97e5a9c78da22053583d05aac411
add test case for fdo#86754

Change-Id: I0f57c1124e62d8946b68c614e3ff09d26b569e77