revlog.revision(): minor cleanup
Rename some variables, making the name more obvious (in particular "cache" was
actually two different variable.
Move code around, moving the index preloading before the deltachain computation,
without that index preloading was useless (everything was read in deltachain).
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0" -d "1000000 0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1" -d "1000000 0"
$ hg update 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo This is file c1 > c
$ hg add c
$ hg commit -m "commit #2" -d "1000000 0"
created new head
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ rm b
$ echo This is file c22 > c
$ hg commit -m "commit #3" -d "1000000 0"