you cannot really automate it: even if there are no outright conflicts, the merge might result in non-working code.
two possibilities for future improvements, in increasing order of preference:
one: commit to trunk, have someone appointed to cherry-pick revisions into the release branch
two: switch to mercurial. srsly. it's very svn-like, and it's impossible to forget a merge, since merging branch A into branch B means adding into B all commits that are in A but not in B
# alice edits some files and commits two revisions
# into her repository, then pushes them into the master
alice ~/wc/stable % hg ci
alice ~/wc/stable % hg ci
alice ~/wc/stable % hg push
pushing to http://repo/stable
searching for changes
...
# bobby tries to push, but oops, his copy is stale
bobby ~/wc/stable % hg ci
bobby ~/wc/stable % hg ci
bobby ~/wc/stable % hg ci
bobby ~/wc/stable % hg push
pushing to http://repo/stable
searching for changes
abort: push creates new remote heads!
(did you forget to merge? use push -f to force)
# bobby must augment his repository such that a push
# to the master will leave the master with a single
# head. this is achieved by pulling changes from
# the master, which will cause *his* repository to have
# two "head" revisions:
bobby ~/wc/stable % hg pull
searching for changes
...
added 2 changesets with 4 changes to 4 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
# he will now merge the heads to reduce them to a single
# head. pushing that into the master will be ok (since
# the result of such a push is a single head)
bobby ~/wc/stable % hg merge
bobby ~/wc/stable % hg ci
bobby ~/wc/stable % hg push
# ok!
you might say this is different from merging between branches, but in mercurial, every working copy is effectively a branch, and both situations are handled with a single set of commands:
alice ~/wc/stable % hg ci
alice ~/wc/stable % hg push
alice ~/wc/stable % logout
# alice went home without merging to trunk
bobby ~/wc/stable % hg pull -u
# alice's changeset is now his (only) head
# he edits a file, commits it, and pushes
bobby ~/wc/stable % hg ci
bobby ~/wc/stable % hg push
# his sole commit goes to the master
# the push is ok since it results in a single head
# bobby goes on to merge stable to trunk
bobby ~/wc/stable % cd ../trunk
bobby ~/wc/trunk % hg pull -u
# pulls changes from trunk master
bobby ~/wc/trunk % hg pull http://repo/stable
# pulls all changesets that are in stable but
# not in (this working copy of) trunk
bobby ~/wc/trunk % hg merge
bobby ~/wc/trunk % hg ci
bobby ~/wc/trunk % hg push
this working copy above is important, but a stale copy won't bite you: if bobby's
working copy was stale WRT the master, the push would fail and prompt him to merge his previous merge with master's new changes before retrying.
