Merge branch 'en/rebase-backend'

"git rebase" has learned to use the merge backend (i.e. the
machinery that drives "rebase -i") by default, while allowing
"--apply" option to use the "apply" backend (e.g. the moral
equivalent of "format-patch piped to am").  The rebase.backend
configuration variable can be set to customize.

* en/rebase-backend:
  rebase: rename the two primary rebase backends
  rebase: change the default backend from "am" to "merge"
  rebase: make the backend configurable via config setting
  rebase tests: repeat some tests using the merge backend instead of am
  rebase tests: mark tests specific to the am-backend with --am
  rebase: drop '-i' from the reflog for interactive-based rebases
  git-prompt: change the prompt for interactive-based rebases
  rebase: add an --am option
  rebase: move incompatibility checks between backend options a bit earlier
  git-rebase.txt: add more details about behavioral differences of backends
  rebase: allow more types of rebases to fast-forward
  t3432: make these tests work with either am or merge backends
  rebase: fix handling of restrict_revision
  rebase: make sure to pass along the quiet flag to the sequencer
  rebase, sequencer: remove the broken GIT_QUIET handling
  t3406: simplify an already simple test
  rebase (interactive-backend): fix handling of commits that become empty
  rebase (interactive-backend): make --keep-empty the default
  t3404: directly test the behavior of interest
  git-rebase.txt: update description of --allow-empty-message

1 files changed, 10 insertions, 9 deletions

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index d79a3ef505..c5ce3ab760 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -72,15 +72,16 @@ test_expect_success 'rebase --keep-empty' '
 	test_line_count = 6 actual
 '
 
-test_expect_success 'rebase -i with empty HEAD' '
+test_expect_success 'rebase -i with empty todo list' '
 	cat >expect <<-\EOF &&
 	error: nothing to do
 	EOF
 	(
 		set_fake_editor &&
-		test_must_fail env FAKE_LINES="1 exec_true" \
-			git rebase -i HEAD^ >actual 2>&1
+		test_must_fail env FAKE_LINES="#" \
+			git rebase -i HEAD^ >output 2>&1
 	) &&
+	tail -n 1 output >actual &&  # Ignore output about changing todo list
 	test_i18ncmp expect actual
 '
 
@@ -222,7 +223,7 @@ test_expect_success 'reflog for the branch shows state before rebase' '
 '
 
 test_expect_success 'reflog for the branch shows correct finish message' '
-	printf "rebase -i (finish): refs/heads/branch1 onto %s\n" \
+	printf "rebase (finish): refs/heads/branch1 onto %s\n" \
 		"$(git rev-parse branch2)" >expected &&
 	git log -g --pretty=%gs -1 refs/heads/branch1 >actual &&
 	test_cmp expected actual
@@ -1137,7 +1138,7 @@ test_expect_success C_LOCALE_OUTPUT 'rebase --edit-todo does not work on non-int
 	git checkout conflict-branch &&
 	(
 		set_fake_editor &&
-		test_must_fail git rebase -f --onto HEAD~2 HEAD~ &&
+		test_must_fail git rebase -f --apply --onto HEAD~2 HEAD~ &&
 		test_must_fail git rebase --edit-todo
 	) &&
 	git rebase --abort
@@ -1161,10 +1162,10 @@ test_expect_success 'rebase -i produces readable reflog' '
 	git branch -f branch-reflog-test H &&
 	git rebase -i --onto I F branch-reflog-test &&
 	cat >expect <<-\EOF &&
-	rebase -i (finish): returning to refs/heads/branch-reflog-test
-	rebase -i (pick): H
-	rebase -i (pick): G
-	rebase -i (start): checkout I
+	rebase (finish): returning to refs/heads/branch-reflog-test
+	rebase (pick): H
+	rebase (pick): G
+	rebase (start): checkout I
 	EOF
 	git reflog -n4 HEAD |
 	sed "s/[^:]*: //" >actual &&