If an edit list is only deletion regions, the B side will wind up
with an empty range as there is no new content to include in the
file. This is a corner case that means we have to always return
false from contains(int) when there is no content.
Change-Id: I745fa9ce2071acc2aa83bd84909477afeef0c3d4
Signed-off-by: Shawn O. Pearce <sop@google.com>
ad34e3b266