git-fetch, git-branch: Support local --track via a special remote '.'

This patch adds support for a dummy remote '.' to avoid having
to declare a fake remote like

        [remote "local"]
                url = .
                fetch = refs/heads/*:refs/heads/*

Such a builtin remote simplifies the operation of "git-fetch",
which will populate FETCH_HEAD but will not pretend that two
repositories are in use, will not create a thin pack, and will
not perform any useless remapping of names.  The speed
improvement is around 20%, and it should improve more if
"git-fetch" is converted to a builtin.

To this end, git-parse-remote is grown with a new kind of
remote, 'builtin'.  In git-fetch.sh, we treat the builtin remote
specially in that it needs no pack/store operations.  In fact,
doing git-fetch on a builtin remote will simply populate
FETCH_HEAD appropriately.

The patch also improves of the --track/--no-track support,
extending it so that branch.<name>.remote items referring '.'
can be created.  Finally, it fixes a typo in git-checkout.sh.

Signed-off-by: Paolo Bonzini  <bonzini@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

2 files changed, 30 insertions, 0 deletions

diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 75c000a96..9558bdb63 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -145,9 +145,15 @@ test_expect_success 'test overriding tracking setup via --no-track' \
      git-config remote.local.fetch refs/heads/*:refs/remotes/local/* &&
      (git-show-ref -q refs/remotes/local/master || git-fetch local) &&
      git-branch --no-track my2 local/master &&
+     git-config branch.autosetupmerge false &&
      ! test $(git-config branch.my2.remote) = local &&
      ! test $(git-config branch.my2.merge) = refs/heads/master'
 
+test_expect_success 'test local tracking setup' \
+    'git branch --track my6 s &&
+     test $(git-config branch.my6.remote) = . &&
+     test $(git-config branch.my6.merge) = refs/heads/s'
+
 # Keep this test last, as it changes the current branch
 cat >expect <<EOF
 0000000000000000000000000000000000000000 $HEAD $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	branch: Created from master
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 7eb37838b..243212d3d 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -29,5 +29,29 @@ test_expect_success 'checking the results' '
 	diff file cloned/file
 '
 
+test_expect_success 'test . as a remote' '
+
+	git branch copy master &&
+	git config branch.copy.remote . &&
+	git config branch.copy.merge refs/heads/master &&
+	echo updated >file &&
+	git commit -a -m updated &&
+	git checkout copy &&
+	test `cat file` = file &&
+	git pull &&
+	test `cat file` = updated
+'
+
+test_expect_success 'the default remote . should not break explicit pull' '
+	git checkout -b second master^ &&
+	echo modified >file &&
+	git commit -a -m modified &&
+	git checkout copy &&
+	git reset --hard HEAD^ &&
+	test `cat file` = file &&
+	git pull . second &&
+	test `cat file` = modified
+'
+
 test_done