Merge branch 'es/rebase-i-no-abbrev' into maint

* es/rebase-i-no-abbrev:
  rebase -i: fix short SHA-1 collision
  t3404: rebase -i: demonstrate short SHA-1 collision
  t3404: make tests more self-contained

Conflicts:
	t/t3404-rebase-interactive.sh

2 files changed, 117 insertions, 2 deletions

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b8245cd3fa..10bf318d0d 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -690,6 +690,32 @@ skip_unnecessary_picks () {
 	die "Could not skip unnecessary pick commands"
 }
 
+transform_todo_ids () {
+	while read -r command rest
+	do
+		case "$command" in
+		"$comment_char"* | exec)
+			# Be careful for oddball commands like 'exec'
+			# that do not have a SHA-1 at the beginning of $rest.
+			;;
+		*)
+			sha1=$(git rev-parse --verify --quiet "$@" ${rest%% *}) &&
+			rest="$sha1 ${rest#* }"
+			;;
+		esac
+		printf '%s\n' "$command${rest:+ }$rest"
+	done <"$todo" >"$todo.new" &&
+	mv -f "$todo.new" "$todo"
+}
+
+expand_todo_ids() {
+	transform_todo_ids
+}
+
+collapse_todo_ids() {
+	transform_todo_ids --short=7
+}
+
 # Rearrange the todo list that has both "pick sha1 msg" and
 # "pick sha1 fixup!/squash! msg" appears in it so that the latter
 # comes immediately after the former, and change "pick" to
@@ -842,6 +868,7 @@ skip)
 edit-todo)
 	git stripspace --strip-comments <"$todo" >"$todo".new
 	mv -f "$todo".new "$todo"
+	collapse_todo_ids
 	append_todo_help
 	git stripspace --comment-lines >>"$todo" <<\EOF
 
@@ -853,6 +880,7 @@ EOF
 
 	git_sequence_editor "$todo" ||
 		die "Could not execute editor"
+	expand_todo_ids
 
 	exit
 	;;
@@ -1009,6 +1037,8 @@ git_sequence_editor "$todo" ||
 has_action "$todo" ||
 	die_abort "Nothing to do"
 
+expand_todo_ids
+
 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
 
 GIT_REFLOG_ACTION="$GIT_REFLOG_ACTION: checkout $onto_name"
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 4dbeddb0de..50e22b1cad 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -29,8 +29,6 @@ Initial setup:
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
-set_fake_editor
-
 # WARNING: Modifications to the initial repository can change the SHA ID used
 # in the expect2 file for the 'stop on conflicting pick' test.
 
@@ -72,6 +70,7 @@ export SHELL
 test_expect_success 'rebase -i with the exec command' '
 	git checkout master &&
 	(
+	set_fake_editor &&
 	FAKE_LINES="1 exec_>touch-one
 		2 exec_>touch-two exec_false exec_>touch-three
 		3 4 exec_>\"touch-file__name_with_spaces\";_>touch-after-semicolon 5" &&
@@ -93,6 +92,7 @@ test_expect_success 'rebase -i with the exec command' '
 test_expect_success 'rebase -i with the exec command runs from tree root' '
 	git checkout master &&
 	mkdir subdir && (cd subdir &&
+	set_fake_editor &&
 	FAKE_LINES="1 exec_>touch-subdir" \
 		git rebase -i HEAD^
 	) &&
@@ -103,6 +103,7 @@ test_expect_success 'rebase -i with the exec command runs from tree root' '
 test_expect_success 'rebase -i with the exec command checks tree cleanness' '
 	git checkout master &&
 	(
+	set_fake_editor &&
 	FAKE_LINES="exec_echo_foo_>file1 1" &&
 	export FAKE_LINES &&
 	test_must_fail git rebase -i HEAD^
@@ -116,6 +117,7 @@ test_expect_success 'rebase -i with exec of inexistent command' '
 	git checkout master &&
 	test_when_finished "git rebase --abort" &&
 	(
+	set_fake_editor &&
 	FAKE_LINES="exec_this-command-does-not-exist 1" &&
 	export FAKE_LINES &&
 	test_must_fail git rebase -i HEAD^ >actual 2>&1
@@ -125,6 +127,7 @@ test_expect_success 'rebase -i with exec of inexistent command' '
 
 test_expect_success 'no changes are a nop' '
 	git checkout branch2 &&
+	set_fake_editor &&
 	git rebase -i F &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch2" &&
 	test $(git rev-parse I) = $(git rev-parse HEAD)
@@ -134,6 +137,7 @@ test_expect_success 'test the [branch] option' '
 	git checkout -b dead-end &&
 	git rm file6 &&
 	git commit -m "stop here" &&
+	set_fake_editor &&
 	git rebase -i F branch2 &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch2" &&
 	test $(git rev-parse I) = $(git rev-parse branch2) &&
@@ -142,6 +146,7 @@ test_expect_success 'test the [branch] option' '
 
 test_expect_success 'test --onto <branch>' '
 	git checkout -b test-onto branch2 &&
+	set_fake_editor &&
 	git rebase -i --onto branch1 F &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/test-onto" &&
 	test $(git rev-parse HEAD^) = $(git rev-parse branch1) &&
@@ -151,6 +156,7 @@ test_expect_success 'test --onto <branch>' '
 test_expect_success 'rebase on top of a non-conflicting commit' '
 	git checkout branch1 &&
 	git tag original-branch1 &&
+	set_fake_editor &&
 	git rebase -i branch2 &&
 	test file6 = $(git diff --name-only original-branch1) &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch1" &&
@@ -163,6 +169,7 @@ test_expect_success 'reflog for the branch shows state before rebase' '
 '
 
 test_expect_success 'exchange two commits' '
+	set_fake_editor &&
 	FAKE_LINES="2 1" git rebase -i HEAD~2 &&
 	test H = $(git cat-file commit HEAD^ | sed -ne \$p) &&
 	test G = $(git cat-file commit HEAD | sed -ne \$p)
@@ -188,6 +195,7 @@ EOF
 
 test_expect_success 'stop on conflicting pick' '
 	git tag new-branch1 &&
+	set_fake_editor &&
 	test_must_fail git rebase -i master &&
 	test "$(git rev-parse HEAD~3)" = "$(git rev-parse master)" &&
 	test_cmp expect .git/rebase-merge/patch &&
@@ -208,6 +216,7 @@ test_expect_success 'abort' '
 test_expect_success 'abort with error when new base cannot be checked out' '
 	git rm --cached file1 &&
 	git commit -m "remove file in base" &&
+	set_fake_editor &&
 	test_must_fail git rebase -i master > output 2>&1 &&
 	grep "The following untracked working tree files would be overwritten by checkout:" \
 		output &&
@@ -222,6 +231,7 @@ test_expect_success 'retain authorship' '
 	test_tick &&
 	GIT_AUTHOR_NAME="Twerp Snog" git commit -m "different author" &&
 	git tag twerp &&
+	set_fake_editor &&
 	git rebase -i --onto master HEAD^ &&
 	git show HEAD | grep "^Author: Twerp Snog"
 '
@@ -232,6 +242,7 @@ test_expect_success 'squash' '
 	test_tick &&
 	GIT_AUTHOR_NAME="Nitfol" git commit -m "nitfol" file7 &&
 	echo "******************************" &&
+	set_fake_editor &&
 	FAKE_LINES="1 squash 2" EXPECT_HEADER_COUNT=2 \
 		git rebase -i --onto master HEAD~2 &&
 	test B = $(cat file7) &&
@@ -244,6 +255,7 @@ test_expect_success 'retain authorship when squashing' '
 
 test_expect_success '-p handles "no changes" gracefully' '
 	HEAD=$(git rev-parse HEAD) &&
+	set_fake_editor &&
 	git rebase -i -p HEAD^ &&
 	git update-index --refresh &&
 	git diff-files --quiet &&
@@ -253,6 +265,7 @@ test_expect_success '-p handles "no changes" gracefully' '
 
 test_expect_failure 'exchange two commits with -p' '
 	git checkout H &&
+	set_fake_editor &&
 	FAKE_LINES="2 1" git rebase -i -p HEAD~2 &&
 	test H = $(git cat-file commit HEAD^ | sed -ne \$p) &&
 	test G = $(git cat-file commit HEAD | sed -ne \$p)
@@ -287,6 +300,7 @@ test_expect_success 'preserve merges with -p' '
 	git commit -m M file1 &&
 	git checkout -b to-be-rebased &&
 	test_tick &&
+	set_fake_editor &&
 	git rebase -i -p --onto branch1 master &&
 	git update-index --refresh &&
 	git diff-files --quiet &&
@@ -301,6 +315,7 @@ test_expect_success 'preserve merges with -p' '
 '
 
 test_expect_success 'edit ancestor with -p' '
+	set_fake_editor &&
 	FAKE_LINES="1 2 edit 3 4" git rebase -i -p HEAD~3 &&
 	echo 2 > unrelated-file &&
 	test_tick &&
@@ -314,6 +329,7 @@ test_expect_success 'edit ancestor with -p' '
 
 test_expect_success '--continue tries to commit' '
 	test_tick &&
+	set_fake_editor &&
 	test_must_fail git rebase -i --onto new-branch1 HEAD^ &&
 	echo resolved > file1 &&
 	git add file1 &&
@@ -325,6 +341,7 @@ test_expect_success '--continue tries to commit' '
 test_expect_success 'verbose flag is heeded, even after --continue' '
 	git reset --hard master@{1} &&
 	test_tick &&
+	set_fake_editor &&
 	test_must_fail git rebase -v -i --onto new-branch1 HEAD^ &&
 	echo resolved > file1 &&
 	git add file1 &&
@@ -334,6 +351,7 @@ test_expect_success 'verbose flag is heeded, even after --continue' '
 
 test_expect_success 'multi-squash only fires up editor once' '
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	FAKE_COMMIT_AMEND="ONCE" FAKE_LINES="1 squash 2 squash 3 squash 4" \
 		EXPECT_HEADER_COUNT=4 \
 		git rebase -i $base &&
@@ -344,6 +362,7 @@ test_expect_success 'multi-squash only fires up editor once' '
 test_expect_success 'multi-fixup does not fire up editor' '
 	git checkout -b multi-fixup E &&
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	FAKE_COMMIT_AMEND="NEVER" FAKE_LINES="1 fixup 2 fixup 3 fixup 4" \
 		git rebase -i $base &&
 	test $base = $(git rev-parse HEAD^) &&
@@ -355,6 +374,7 @@ test_expect_success 'multi-fixup does not fire up editor' '
 test_expect_success 'commit message used after conflict' '
 	git checkout -b conflict-fixup conflict-branch &&
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	(
 		FAKE_LINES="1 fixup 3 fixup 4" &&
 		export FAKE_LINES &&
@@ -373,6 +393,7 @@ test_expect_success 'commit message used after conflict' '
 test_expect_success 'commit message retained after conflict' '
 	git checkout -b conflict-squash conflict-branch &&
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	(
 		FAKE_LINES="1 fixup 3 squash 4" &&
 		export FAKE_LINES &&
@@ -399,6 +420,7 @@ EOF
 test_expect_success 'squash and fixup generate correct log messages' '
 	git checkout -b squash-fixup E &&
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	FAKE_COMMIT_AMEND="ONCE" FAKE_LINES="1 fixup 2 squash 3 fixup 4" \
 		EXPECT_HEADER_COUNT=4 \
 		git rebase -i $base &&
@@ -411,6 +433,7 @@ test_expect_success 'squash and fixup generate correct log messages' '
 test_expect_success 'squash ignores comments' '
 	git checkout -b skip-comments E &&
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	FAKE_COMMIT_AMEND="ONCE" FAKE_LINES="# 1 # squash 2 # squash 3 # squash 4 #" \
 		EXPECT_HEADER_COUNT=4 \
 		git rebase -i $base &&
@@ -423,6 +446,7 @@ test_expect_success 'squash ignores comments' '
 test_expect_success 'squash ignores blank lines' '
 	git checkout -b skip-blank-lines E &&
 	base=$(git rev-parse HEAD~4) &&
+	set_fake_editor &&
 	FAKE_COMMIT_AMEND="ONCE" FAKE_LINES="> 1 > squash 2 > squash 3 > squash 4 >" \
 		EXPECT_HEADER_COUNT=4 \
 		git rebase -i $base &&
@@ -435,6 +459,7 @@ test_expect_success 'squash ignores blank lines' '
 test_expect_success 'squash works as expected' '
 	git checkout -b squash-works no-conflict-branch &&
 	one=$(git rev-parse HEAD~3) &&
+	set_fake_editor &&
 	FAKE_LINES="1 squash 3 2" EXPECT_HEADER_COUNT=2 \
 		git rebase -i HEAD~3 &&
 	test $one = $(git rev-parse HEAD~2)
@@ -443,6 +468,7 @@ test_expect_success 'squash works as expected' '
 test_expect_success 'interrupted squash works as expected' '
 	git checkout -b interrupted-squash conflict-branch &&
 	one=$(git rev-parse HEAD~3) &&
+	set_fake_editor &&
 	(
 		FAKE_LINES="1 squash 3 2" &&
 		export FAKE_LINES &&
@@ -460,6 +486,7 @@ test_expect_success 'interrupted squash works as expected' '
 test_expect_success 'interrupted squash works as expected (case 2)' '
 	git checkout -b interrupted-squash2 conflict-branch &&
 	one=$(git rev-parse HEAD~3) &&
+	set_fake_editor &&
 	(
 		FAKE_LINES="3 squash 1 2" &&
 		export FAKE_LINES &&
@@ -484,6 +511,7 @@ test_expect_success '--continue tries to commit, even for "edit"' '
 	git commit -m "unrelated change" &&
 	parent=$(git rev-parse HEAD^) &&
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES="edit 1" git rebase -i HEAD^ &&
 	echo edited > file7 &&
 	git add file7 &&
@@ -496,6 +524,7 @@ test_expect_success '--continue tries to commit, even for "edit"' '
 test_expect_success 'aborted --continue does not squash commits after "edit"' '
 	old=$(git rev-parse HEAD) &&
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES="edit 1" git rebase -i HEAD^ &&
 	echo "edited again" > file7 &&
 	git add file7 &&
@@ -510,6 +539,7 @@ test_expect_success 'aborted --continue does not squash commits after "edit"' '
 
 test_expect_success 'auto-amend only edited commits after "edit"' '
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES="edit 1" git rebase -i HEAD^ &&
 	echo "edited again" > file7 &&
 	git add file7 &&
@@ -528,6 +558,7 @@ test_expect_success 'auto-amend only edited commits after "edit"' '
 test_expect_success 'clean error after failed "exec"' '
 	test_tick &&
 	test_when_finished "git rebase --abort || :" &&
+	set_fake_editor &&
 	(
 		FAKE_LINES="1 exec_false" &&
 		export FAKE_LINES &&
@@ -543,6 +574,7 @@ test_expect_success 'rebase a detached HEAD' '
 	grandparent=$(git rev-parse HEAD~2) &&
 	git checkout $(git rev-parse HEAD) &&
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES="2 1" git rebase -i HEAD~2 &&
 	test $grandparent = $(git rev-parse HEAD~2)
 '
@@ -559,6 +591,7 @@ test_expect_success 'rebase a commit violating pre-commit' '
 	test_must_fail git commit -m doesnt-verify file1 &&
 	git commit -m doesnt-verify --no-verify file1 &&
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES=2 git rebase -i HEAD~2
 
 '
@@ -580,6 +613,7 @@ test_expect_success 'rebase with a file named HEAD in worktree' '
 		git commit -m "Add body"
 	) &&
 
+	set_fake_editor &&
 	FAKE_LINES="1 squash 2" git rebase -i to-be-rebased &&
 	test "$(git show -s --pretty=format:%an)" = "Squashed Away"
 
@@ -591,6 +625,7 @@ test_expect_success 'do "noop" when there is nothing to cherry-pick' '
 	GIT_EDITOR=: git commit --amend \
 		--author="Somebody else <somebody@else.com>" &&
 	test $(git rev-parse branch3) != $(git rev-parse branch4) &&
+	set_fake_editor &&
 	git rebase -i branch3 &&
 	test $(git rev-parse branch3) = $(git rev-parse branch4)
 
@@ -615,10 +650,12 @@ test_expect_success 'submodule rebase setup' '
 		git commit -a -m "submodule second"
 	) &&
 	test_tick &&
+	set_fake_editor &&
 	git commit -a -m "Three changes submodule"
 '
 
 test_expect_success 'submodule rebase -i' '
+	set_fake_editor &&
 	FAKE_LINES="1 squash 2 3" git rebase -i A
 '
 
@@ -636,6 +673,7 @@ test_expect_success 'submodule conflict setup' '
 '
 
 test_expect_success 'rebase -i continue with only submodule staged' '
+	set_fake_editor &&
 	test_must_fail git rebase -i submodule-base &&
 	git add sub &&
 	git rebase --continue &&
@@ -645,6 +683,7 @@ test_expect_success 'rebase -i continue with only submodule staged' '
 test_expect_success 'rebase -i continue with unstaged submodule' '
 	git checkout submodule-topic &&
 	git reset --hard &&
+	set_fake_editor &&
 	test_must_fail git rebase -i submodule-base &&
 	git reset &&
 	git rebase --continue &&
@@ -657,6 +696,7 @@ test_expect_success 'avoid unnecessary reset' '
 	test-chmtime =123456789 file3 &&
 	git update-index --refresh &&
 	HEAD=$(git rev-parse HEAD) &&
+	set_fake_editor &&
 	git rebase -i HEAD~4 &&
 	test $HEAD = $(git rev-parse HEAD) &&
 	MTIME=$(test-chmtime -v +0 file3 | sed 's/[^0-9].*$//') &&
@@ -665,6 +705,7 @@ test_expect_success 'avoid unnecessary reset' '
 
 test_expect_success 'reword' '
 	git checkout -b reword-branch master &&
+	set_fake_editor &&
 	FAKE_LINES="1 2 3 reword 4" FAKE_COMMIT_MESSAGE="E changed" git rebase -i A &&
 	git show HEAD | grep "E changed" &&
 	test $(git rev-parse master) != $(git rev-parse HEAD) &&
@@ -684,6 +725,7 @@ test_expect_success 'rebase -i can copy notes' '
 	test_commit n2 &&
 	test_commit n3 &&
 	git notes add -m"a note" n3 &&
+	set_fake_editor &&
 	git rebase -i --onto n1 n2 &&
 	test "a note" = "$(git notes show HEAD)"
 '
@@ -697,6 +739,7 @@ EOF
 test_expect_success 'rebase -i can copy notes over a fixup' '
 	git reset --hard n3 &&
 	git notes add -m"an earlier note" n2 &&
+	set_fake_editor &&
 	GIT_NOTES_REWRITE_MODE=concatenate FAKE_LINES="1 fixup 2" git rebase -i n1 &&
 	git notes show > output &&
 	test_cmp expect output
@@ -706,6 +749,7 @@ test_expect_success 'rebase while detaching HEAD' '
 	git symbolic-ref HEAD &&
 	grandparent=$(git rev-parse HEAD~2) &&
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES="2 1" git rebase -i HEAD~2 HEAD^0 &&
 	test $grandparent = $(git rev-parse HEAD~2) &&
 	test_must_fail git symbolic-ref HEAD
@@ -715,6 +759,7 @@ test_tick # Ensure that the rebased commits get a different timestamp.
 test_expect_success 'always cherry-pick with --no-ff' '
 	git checkout no-ff-branch &&
 	git tag original-no-ff-branch &&
+	set_fake_editor &&
 	git rebase -i --no-ff A &&
 	touch empty &&
 	for p in 0 1 2
@@ -747,6 +792,7 @@ test_expect_success 'set up commits with funny messages' '
 test_expect_success 'rebase-i history with funny messages' '
 	git rev-list A..funny >expect &&
 	test_tick &&
+	set_fake_editor &&
 	FAKE_LINES="1 2 3 4" git rebase -i A &&
 	git rev-list A.. >actual &&
 	test_cmp expect actual
@@ -763,6 +809,7 @@ test_expect_success 'prepare for rebase -i --exec' '
 
 
 test_expect_success 'running "git rebase -i --exec git show HEAD"' '
+	set_fake_editor &&
 	git rebase -i --exec "git show HEAD" HEAD~2 >actual &&
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
@@ -776,6 +823,7 @@ test_expect_success 'running "git rebase -i --exec git show HEAD"' '
 
 test_expect_success 'running "git rebase --exec git show HEAD -i"' '
 	git reset --hard execute &&
+	set_fake_editor &&
 	git rebase --exec "git show HEAD" -i HEAD~2 >actual &&
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
@@ -789,6 +837,7 @@ test_expect_success 'running "git rebase --exec git show HEAD -i"' '
 
 test_expect_success 'running "git rebase -ix git show HEAD"' '
 	git reset --hard execute &&
+	set_fake_editor &&
 	git rebase -ix "git show HEAD" HEAD~2 >actual &&
 	(
 		FAKE_LINES="1 exec_git_show_HEAD 2 exec_git_show_HEAD" &&
@@ -802,6 +851,7 @@ test_expect_success 'running "git rebase -ix git show HEAD"' '
 
 test_expect_success 'rebase -ix with several <CMD>' '
 	git reset --hard execute &&
+	set_fake_editor &&
 	git rebase -ix "git show HEAD; pwd" HEAD~2 >actual &&
 	(
 		FAKE_LINES="1 exec_git_show_HEAD;_pwd 2 exec_git_show_HEAD;_pwd" &&
@@ -815,6 +865,7 @@ test_expect_success 'rebase -ix with several <CMD>' '
 
 test_expect_success 'rebase -ix with several instances of --exec' '
 	git reset --hard execute &&
+	set_fake_editor &&
 	git rebase -i --exec "git show HEAD" --exec "pwd" HEAD~2 >actual &&
 	(
 		FAKE_LINES="1 exec_git_show_HEAD exec_pwd 2
@@ -836,6 +887,7 @@ test_expect_success 'rebase -ix with --autosquash' '
 	echo bis >bis.txt &&
 	git add bis.txt &&
 	git commit -m "fixup! two_exec" &&
+	set_fake_editor &&
 	(
 		git checkout -b autosquash_actual &&
 		git rebase -i --exec "git show HEAD" --autosquash HEAD~4 >actual
@@ -854,6 +906,7 @@ test_expect_success 'rebase -ix with --autosquash' '
 
 test_expect_success 'rebase --exec without -i shows error message' '
 	git reset --hard execute &&
+	set_fake_editor &&
 	test_must_fail git rebase --exec "git show HEAD" HEAD~2 2>actual &&
 	echo "The --exec option must be used with the --interactive option" >expected &&
 	test_i18ncmp expected actual
@@ -862,6 +915,7 @@ test_expect_success 'rebase --exec without -i shows error message' '
 
 test_expect_success 'rebase -i --exec without <CMD>' '
 	git reset --hard execute &&
+	set_fake_editor &&
 	test_must_fail git rebase -i --exec 2>tmp &&
 	sed -e "1d" tmp >actual &&
 	test_must_fail git rebase -h >expected &&
@@ -871,6 +925,7 @@ test_expect_success 'rebase -i --exec without <CMD>' '
 
 test_expect_success 'rebase -i --root re-order and drop commits' '
 	git checkout E &&
+	set_fake_editor &&
 	FAKE_LINES="3 1 2 5" git rebase -i --root &&
 	test E = $(git cat-file commit HEAD | sed -ne \$p) &&
 	test B = $(git cat-file commit HEAD^ | sed -ne \$p) &&
@@ -884,6 +939,7 @@ test_expect_success 'rebase -i --root retain root commit author and message' '
 	echo B >file7 &&
 	git add file7 &&
 	GIT_AUTHOR_NAME="Twerp Snog" git commit -m "different author" &&
+	set_fake_editor &&
 	FAKE_LINES="2" git rebase -i --root &&
 	git cat-file commit HEAD | grep -q "^author Twerp Snog" &&
 	git cat-file commit HEAD | grep -q "^different author$"
@@ -892,6 +948,7 @@ test_expect_success 'rebase -i --root retain root commit author and message' '
 test_expect_success 'rebase -i --root temporary sentinel commit' '
 	git checkout B &&
 	(
+		set_fake_editor &&
 		FAKE_LINES="2" &&
 		export FAKE_LINES &&
 		test_must_fail git rebase -i --root
@@ -902,6 +959,7 @@ test_expect_success 'rebase -i --root temporary sentinel commit' '
 
 test_expect_success 'rebase -i --root fixup root commit' '
 	git checkout B &&
+	set_fake_editor &&
 	FAKE_LINES="1 fixup 2" git rebase -i --root &&
 	test A = $(git cat-file commit HEAD | sed -ne \$p) &&
 	test B = $(git show HEAD:file1) &&
@@ -911,6 +969,7 @@ test_expect_success 'rebase -i --root fixup root commit' '
 test_expect_success 'rebase --edit-todo does not works on non-interactive rebase' '
 	git reset --hard &&
 	git checkout conflict-branch &&
+	set_fake_editor &&
 	test_must_fail git rebase --onto HEAD~2 HEAD~ &&
 	test_must_fail git rebase --edit-todo &&
 	git rebase --abort
@@ -919,6 +978,7 @@ test_expect_success 'rebase --edit-todo does not works on non-interactive rebase
 test_expect_success 'rebase --edit-todo can be used to modify todo' '
 	git reset --hard &&
 	git checkout no-conflict-branch^0 &&
+	set_fake_editor &&
 	FAKE_LINES="edit 1 2 3" git rebase -i HEAD~3 &&
 	FAKE_LINES="2 1" git rebase --edit-todo &&
 	git rebase --continue
@@ -929,6 +989,7 @@ test_expect_success 'rebase --edit-todo can be used to modify todo' '
 test_expect_success 'rebase -i produces readable reflog' '
 	git reset --hard &&
 	git branch -f branch-reflog-test H &&
+	set_fake_editor &&
 	git rebase -i --onto I F branch-reflog-test &&
 	cat >expect <<-\EOF &&
 	rebase -i (start): checkout I
@@ -989,4 +1050,28 @@ test_expect_success 'rebase -i error on commits with \ in message' '
 	test_expect_code 1 grep  "	emp" error
 '
 
+test_expect_success 'short SHA-1 setup' '
+	test_when_finished "git checkout master" &&
+	git checkout --orphan collide &&
+	git rm -rf . &&
+	(
+	unset test_tick &&
+	test_commit collide1 collide &&
+	test_commit --notick collide2 collide &&
+	test_commit --notick collide3 collide
+	)
+'
+
+test_expect_success 'short SHA-1 collide' '
+	test_when_finished "reset_rebase && git checkout master" &&
+	git checkout collide &&
+	(
+	unset test_tick &&
+	test_tick &&
+	set_fake_editor &&
+	FAKE_COMMIT_MESSAGE="collide2 ac4f2ee" \
+	FAKE_LINES="reword 1 2" git rebase -i HEAD~2
+	)
+'
+
 test_done