$ mkdir t
$ cd t
$ 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"
$ rm b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg add b
$ hg commit -m "commit #2" -d "1000000 0"
created new head
$ cd ..; rm -r t
$ mkdir t
$ cd t
$ 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"
$ rm b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg commit -A -m "commit #2" -d "1000000 0"
adding b
created new head
$ cd ..; rm -r t
$ mkdir t
$ cd t
$ 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"
$ rm b
$ hg remove b
$ hg update 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo This is file b2 > b
$ hg commit -A -m "commit #2" -d "1000000 0"
adding b
created new head