add prechangegroup and pretxnchangegroup hooks.
prechangegroup lets you stop push, pull or unbundle before it begins.
pretxnchangegroup lets you inspect changegroup before transaction is
committed, and roll back if you not like it.
#!/bin/sh
hg init
echo foo > a
hg add a
hg commit -m "1" -d "0 0"
echo bar > b
hg add b
hg remove a
echo "%%% should show a removed and b added"
hg status
echo "reverting..."
hg revert
echo "%%% should show b unknown and a back to normal"
hg status
rm b
hg co -C 0
echo foo-a > a
hg commit -m "2a" -d "0 0"
hg co -C 0
echo foo-b > a
hg commit -m "2b" -d "0 0"
HGMERGE=true hg update -m 1
echo "%%% should show foo-b"
cat a
echo bar > b
hg add b
rm a
hg remove a
echo "%%% should show a removed and b added"
hg status
echo "reverting..."
hg revert
echo "%%% should show b unknown and a marked modified (merged)"
hg status
echo "%%% should show foo-b"
cat a