Previously the logic around hitting the end of the file without having
found the insertion point didn't account for the fact that you might
be in roughly the right area, and would not need to duplicate the meta
section or section headers.
This takes that into account during the else phase. It will help with
the neutron functional jobs that merge a lot of snippets together.
Change-Id: Ifaa1176e9fdfbc4fdb43192ed2f85e7306823848