Add revlog.strip to truncate away revisions.
This updates the revlog data structures for index and nodemap in place
so the .d and .i files don't need to be reread after stripping away a revision.
#!/usr/bin/env python
import sys, os
from mercurial import hg
f = sys.argv[1]
r1 = hg.revlog(open, f + ".i", f + ".d")
r2 = hg.revlog(open, f + ".i2", f + ".d2")
tr = hg.transaction(open, "journal")
for i in xrange(r1.count()):
n = r1.node(i)
p1, p2 = r1.parents(n)
l = r1.linkrev(n)
t = r1.revision(n)
n2 = r2.addrevision(t, tr, l, p1, p2)
tr.close()
os.rename(f + ".i", f + ".i.old")
os.rename(f + ".d", f + ".d.old")
os.rename(f + ".i2", f + ".i")
os.rename(f + ".d2", f + ".d")