extend network protocol to stop clients from locking servers
now all repositories have capabilities slot, tuple with list of names.
if 'unbundle' capability present, repo supports push where client does
not need to lock server. repository classes that have unbundle capability
also have unbundle method.
implemented for ssh now, will be base for push over http.
unbundle protocol acts this way. server tells client what heads it
has during normal negotiate step. client starts unbundle by repeat
server's heads back to it. if server has new heads, abort immediately.
otherwise, transfer changes to server. once data transferred, server
locks and checks heads again. if heads same, changes can be added.
else someone else added heads, and server aborts.
if client wants to force server to add heads, sends special heads list of
'force'.
#!/bin/sh -e
umask 027
mkdir test1
cd test1
hg init
touch a b
hg add a b
hg ci -m "added a b" -d "1000000 0"
cd ..
mkdir test2
cd test2
hg init
hg pull ../test1
hg co
chmod +x a
hg ci -m "chmod +x a" -d "1000000 0"
cd ../test1
echo 123 >>a
hg ci -m "a updated" -d "1000000 0"
hg pull ../test2
hg heads
hg history
hg -v merge
ls -l ../test[12]/a > foo
cut -b 1-10 < foo