Fix hg clone race with writer
Most read operations in hg don't need locks because we order reads and
writes for consistency. Clone is an exception to this as we're copying
entire file histories and could end up with more file history copied
than we have commits.
For now, make clone take a lock on the source repo. Non-hardlinked
clone should eventually be changed to use lockless pull.
#!/bin/sh
hg --debug init
echo this is a1 > a
hg add a
hg commit -m0 -d "0 0"
echo this is b1 > b
hg add b
hg commit -m1 -d "0 0"
hg manifest 1
echo this is c1 > c
hg rawcommit -p 1 -d "0 0" -m2 c
hg manifest 2
hg parents
rm b
hg rawcommit -p 2 -d "0 0" -m3 b
hg manifest 3
hg parents
echo this is a22 > a
hg rawcommit -p 3 -d "0 0" -m4 a
hg manifest 4
hg parents
echo this is c22 > c
hg rawcommit -p 1 -d "0 0" -m5 c
hg manifest 5
hg parents
# merge, but no files changed
hg rawcommit -p 4 -p 5 -d "0 0" -m6
hg manifest 6
hg parents
# no changes what-so-ever
hg rawcommit -p 6 -d "0 0" -m7
hg manifest 7
hg parents