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 "added file1" > file1
echo "added file2" > file2
hg add file1 file2
hg commit -m "added file1 and file2" -d "0 0" -u user
echo "changed file1" >> file1
hg commit -m "changed file1" -d "0 0" -u user
hg -q log
hg id
hg update -C 0
hg id
echo "changed file1" >> file1
hg id
hg revert
hg diff
hg status
hg id
hg update
hg diff
hg status
hg id
hg update -C 0
echo "changed file1" >> file1
HGMERGE=merge hg update
hg diff
hg status
hg id
hg revert
hg diff
hg status
hg id
hg revert -r tip
hg diff
hg status
hg id
hg update -C
hg diff
hg status
hg id
cd ..; /bin/rm -rf t