[PATCH 5/5] Make 'stg pull' use git-fetch and not git-pull.

[Yann Dirson <ydirson@altern.org>]

We introduce a new pull-does-rebase setting, as companion to pullcmd.
This allows to use both pullcmd's that need a rebase (like git-fetch)
and pullcmd's that do not (like git-pull).

To be able to rebase, we rely on parent information being available
for the stack.

Signed-off-by: Yann Dirson <ydirson@altern.org>
---

 examples/gitconfig |    8 +++++++-
 stgit/config.py    |    3 ++-
 stgit/git.py       |   15 ++++++++++-----
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/examples/gitconfig b/examples/gitconfig
index 5e7b240..e3d9889 100644
--- a/examples/gitconfig
+++ b/examples/gitconfig
@@ -33,8 +33,14 @@
 	#pager = ~/share/stgit/contrib/diffcol.sh
 	#pager = filterdiff --annotate | colordiff | less -FRX
 
-	# GIT pull command (should take the same arguments as git-pull)
+	# GIT pull command (should take the same arguments as
+	# git-fetch or git-pull).  By default:
+	#pullcmd = git-fetch
+	#pull-does-rebase = yes
+	# Alternative (old behaviour), less intuitive but maybe useful
+	# for some workflows:
 	#pullcmd = git-pull
+	#pull-does-rebase = no
 
 	# The three-way merge tool. Note that the 'output' file contains the
 	# same data as 'branch1'. This is useful for tools that do not take an
diff --git a/stgit/config.py b/stgit/config.py
index f5fbdab..0d4da06 100644
--- a/stgit/config.py
+++ b/stgit/config.py
@@ -65,7 +65,8 @@ def config_setup():
     config.set('stgit', 'autoresolved', 'no')
     config.set('stgit', 'smtpserver', 'localhost:25')
     config.set('stgit', 'smtpdelay', '5')
-    config.set('stgit', 'pullcmd', 'git-pull')
+    config.set('stgit', 'pullcmd', 'git-fetch')
+    config.set('stgit', 'pull-does-rebase', 'yes')
     config.set('stgit', 'merger',
                'diff3 -L current -L ancestor -L patched -m -E ' \
                '"%(branch1)s" "%(ancestor)s" "%(branch2)s" > "%(output)s"')
diff --git a/stgit/git.py b/stgit/git.py
index 3c2c237..82b5bf5 100644
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -806,18 +806,23 @@ def reset(files = None, tree_id = None, check_out = True):
         __set_head(tree_id)
 
 def pull(repository = 'origin', refspec = None):
-    """Pull changes from the remote repository. At the moment, just
-    use the 'git-pull' command
+    """Pull changes from the remote repository. Uses 'git-fetch'
+    and moves the stack base.
     """
-    # 'git-pull' updates the HEAD
+    # we update the HEAD
     __clear_head_cache()
 
     args = [repository]
     if refspec:
         args.append(refspec)
 
-    if __run(config.get('stgit', 'pullcmd'), args) != 0:
-        raise GitException, 'Failed "git-pull %s"' % repository
+    command = config.get('stgit', 'pullcmd')
+    if __run(command, args) != 0:
+        raise GitException, 'Failed "%s %s"' % (command, repository)
+
+    if (config.get('stgit', 'pull-does-rebase')):
+        # FIXME!
+        reset(tree_id = rev_parse(repository))
 
 def repack():
     """Repack all objects into a single pack