push: introduce new push.default mode "simple"

When calling "git push" without argument, we want to allow Git to do
something simple to explain and safe. push.default=matching is unsafe
when used to push to shared repositories, and hard to explain to
beginners in some contexts. It is debatable whether 'upstream' or
'current' is the safest or the easiest to explain, so introduce a new
mode called 'simple' that is the intersection of them: push to the
upstream branch, but only if it has the same name remotely. If not, give
an error that suggests the right command to push explicitely to
'upstream' or 'current'.

A question is whether to allow pushing when no upstream is configured. An
argument in favor of allowing the push is that it makes the new mode work
in more cases. On the other hand, refusing to push when no upstream is
configured encourages the user to set the upstream, which will be
beneficial on the next pull. Lacking better argument, we chose to deny
the push, because it will be easier to change in the future if someone
shows us wrong.

Original-patch-by: Jeff King <peff@peff.net>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/t/t5528-push-default.sh b/t/t5528-push-default.sh
index 99e5519263..4736da8f36 100755
--- a/t/t5528-push-default.sh
+++ b/t/t5528-push-default.sh
@@ -71,4 +71,48 @@ test_expect_success '"upstream" does not push when remotes do not match' '
 	test_must_fail git push parent2
 '
 
+test_expect_success 'push from/to new branch with upstream, matching and simple' '
+	git checkout -b new-branch &&
+	test_push_failure simple &&
+	test_push_failure matching &&
+	test_push_failure upstream
+'
+
+test_expect_success 'push from/to new branch with current creates remote branch' '
+	test_config branch.new-branch.remote repo1 &&
+	git checkout new-branch &&
+	test_push_success current new-branch
+'
+
+test_expect_success 'push to existing branch, with no upstream configured' '
+	test_config branch.master.remote repo1 &&
+	git checkout master &&
+	test_push_failure simple &&
+	test_push_failure upstream
+'
+
+test_expect_success 'push to existing branch, upstream configured with same name' '
+	test_config branch.master.remote repo1 &&
+	test_config branch.master.merge refs/heads/master &&
+	git checkout master &&
+	test_commit six &&
+	test_push_success upstream master &&
+	test_commit seven &&
+	test_push_success simple master
+'
+
+test_expect_success 'push to existing branch, upstream configured with different name' '
+	test_config branch.master.remote repo1 &&
+	test_config branch.master.merge refs/heads/other-name &&
+	git checkout master &&
+	test_commit eight &&
+	test_push_success upstream other-name &&
+	test_commit nine &&
+	test_push_failure simple &&
+	git --git-dir=repo1 log -1 --format="%h %s" "other-name" >expect-other-name &&
+	test_push_success current master &&
+	git --git-dir=repo1 log -1 --format="%h %s" "other-name" >actual-other-name &&
+	test_cmp expect-other-name actual-other-name
+'
+
 test_done