sparse-revlog: skip the span check in the sparse-revlog case
This significantly improves the performance on unbundling on smaller
repositories.
Mercurial: unbundling 1K revisions
no-sparse-revlog: 500 ms
sparse-revlog-before: 689 ms
sparse-revlog-after: 484 ms
Pypy: unbundling 1K revisions
no-sparse-revlog: 1.242 s
sparse-revlog-before: 1.135 s
sparse-revlog-after: 0.860 s
NetBeans: unbundling 1K revisions
no-sparse-revlog: 1.386 s
sparse-revlog-before: 2.368 s
sparse-revlog-after: 1.191 s
Mozilla: unbundling 1K revisions
no-sparse-revlog: 3.103 s
sparse-revlog-before: 3.367 s
sparse-revlog-after: 3.093 s
$ hg init
$ touch unknown
$ touch a
$ hg add a
$ hg ci -m "1"
$ touch b
$ hg add b
$ hg ci -m "2"
Should show unknown
$ hg status
? unknown
$ hg revert -r 0 --all
removing b
Should show unknown and b removed
$ hg status
R b
? unknown
Should show a and unknown
$ ls
a
unknown