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
mkdir t
cd t
hg init
echo This is file a1 > a
echo This is file b1 > b
hg add a b
hg commit -m "commit #0" -d "0 0"
echo This is file b22 > b
hg commit -m"comment #1" -d "0 0"
hg update 0
rm b
hg commit -A -m"comment #2" -d "0 0"
# in theory, we shouldn't need the "yes k" below, but it prevents
# this test from hanging when "hg update" erroneously prompts the
# user for "keep or delete"
yes k | hg update 1
# we exit with 0 to avoid the unavoidable SIGPIPE from above causing
# us to fail this test
exit 0