The reason is that filelog.renamed() indirectly calls filelog.revision(),
which is what accesses the full text. However, LFS wraps filelog.renamed()
and completely handles the case where an LFS blob is in play by using rawdata.
I've got a test to demonstrate that this is the case, and prevent regressions.
But the skipread flag is set on all lfs revisions when using --no-lfs,
regardless of whether or not the blobs are local. Just above this, that flag is
consulted, causing the rename checks to be skipped. That will need to be
loosened up first.