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
echo '# basic operation'
hg init basic
cd basic
echo a > a
hg commit -d '0 0' -A -m a
echo b >> a
hg commit -d '1 0' -m b
hg backout -d '2 0' tip
cat a
echo '# file that was removed is recreated'
cd ..
hg init remove
cd remove
echo content > a
hg commit -d '0 0' -A -m a
hg rm a
hg commit -d '1 0' -m b
hg backout -d '2 0' --merge tip
cat a
echo '# backout of backout is as if nothing happened'
hg backout -d '3 0' --merge tip
cat a 2>/dev/null || echo cat: a: No such file or directory
echo '# backout with merge'
cd ..
hg init merge
cd merge
echo line 1 > a
hg commit -d '0 0' -A -m a
echo line 2 >> a
hg commit -d '1 0' -m b
echo line 3 >> a
hg commit -d '2 0' -m c
hg backout --merge -d '3 0' 1
hg commit -d '4 0' -m d
cat a
exit 0