Merge branch 'dl/merge-autostash'

"git merge" learns the "--autostash" option.

* dl/merge-autostash: (22 commits)
  pull: pass --autostash to merge
  t5520: make test_pull_autostash() accept expect_parent_num
  merge: teach --autostash option
  sequencer: implement apply_autostash_oid()
  sequencer: implement save_autostash()
  sequencer: unlink autostash in apply_autostash()
  sequencer: extract perform_autostash() from rebase
  rebase: generify create_autostash()
  rebase: extract create_autostash()
  reset: extract reset_head() from rebase
  rebase: generify reset_head()
  rebase: use apply_autostash() from sequencer.c
  sequencer: rename stash_sha1 to stash_oid
  sequencer: make apply_autostash() accept a path
  rebase: use read_oneliner()
  sequencer: make read_oneliner() extern
  sequencer: configurably warn on non-existent files
  sequencer: make read_oneliner() accept flags
  sequencer: make file exists check more efficient
  sequencer: stop leaking buf
  ...

3 files changed, 208 insertions, 25 deletions

diff --git a/t/t3033-merge-toplevel.sh b/t/t3033-merge-toplevel.sh
index d314599428..e29c284b9b 100755
--- a/t/t3033-merge-toplevel.sh
+++ b/t/t3033-merge-toplevel.sh
@@ -142,6 +142,17 @@ test_expect_success 'refuse two-project merge by default' '
 	test_must_fail git merge five
 '
 
+test_expect_success 'refuse two-project merge by default, quit before --autostash happens' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff >expect &&
+	test_must_fail git merge --autostash five 2>err &&
+	test_i18ngrep ! "stash" err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'two-project merge with --allow-unrelated-histories' '
 	t3033_reset &&
 	git reset --hard four &&
@@ -149,4 +160,15 @@ test_expect_success 'two-project merge with --allow-unrelated-histories' '
 	git diff --exit-code five
 '
 
+test_expect_success 'two-project merge with --allow-unrelated-histories with --autostash' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff one.t >expect &&
+	git merge --allow-unrelated-histories --autostash five 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff one.t >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 2f86fca042..37535d63a9 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -10,11 +10,13 @@ modify () {
 }
 
 test_pull_autostash () {
+	expect_parent_num="$1" &&
+	shift &&
 	git reset --hard before-rebase &&
 	echo dirty >new_file &&
 	git add new_file &&
 	git pull "$@" . copy &&
-	test_cmp_rev HEAD^ copy &&
+	test_cmp_rev HEAD^"$expect_parent_num" copy &&
 	echo dirty >expect &&
 	test_cmp expect new_file &&
 	echo "modified again" >expect &&
@@ -26,7 +28,7 @@ test_pull_autostash_fail () {
 	echo dirty >new_file &&
 	git add new_file &&
 	test_must_fail git pull "$@" . copy 2>err &&
-	test_i18ngrep "uncommitted changes." err
+	test_i18ngrep "\(uncommitted changes.\)\|\(overwritten by merge:\)" err
 }
 
 test_expect_success setup '
@@ -369,22 +371,22 @@ test_expect_success '--rebase fails with multiple branches' '
 
 test_expect_success 'pull --rebase succeeds with dirty working directory and rebase.autostash set' '
 	test_config rebase.autostash true &&
-	test_pull_autostash --rebase
+	test_pull_autostash 1 --rebase
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash=true' '
 	test_config rebase.autostash true &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash=false' '
 	test_config rebase.autostash false &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash unset' '
 	test_unconfig rebase.autostash &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --no-autostash & rebase.autostash=true' '
@@ -402,13 +404,40 @@ test_expect_success 'pull --rebase --no-autostash & rebase.autostash unset' '
 	test_pull_autostash_fail --rebase --no-autostash
 '
 
-for i in --autostash --no-autostash
-do
-	test_expect_success "pull $i (without --rebase) is illegal" '
-		test_must_fail git pull $i . copy 2>err &&
-		test_i18ngrep "only valid with --rebase" err
-	'
-done
+test_expect_success 'pull succeeds with dirty working directory and merge.autostash set' '
+	test_config merge.autostash true &&
+	test_pull_autostash 2
+'
+
+test_expect_success 'pull --autostash & merge.autostash=true' '
+	test_config merge.autostash true &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --autostash & merge.autostash=false' '
+	test_config merge.autostash false &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --autostash & merge.autostash unset' '
+	test_unconfig merge.autostash &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash=true' '
+	test_config merge.autostash true &&
+	test_pull_autostash_fail --no-autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash=false' '
+	test_config merge.autostash false &&
+	test_pull_autostash_fail --no-autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash unset' '
+	test_unconfig merge.autostash &&
+	test_pull_autostash_fail --no-autostash
+'
 
 test_expect_success 'pull.rebase' '
 	git reset --hard before-rebase &&
@@ -422,7 +451,7 @@ test_expect_success 'pull.rebase' '
 
 test_expect_success 'pull --autostash & pull.rebase=true' '
 	test_config pull.rebase true &&
-	test_pull_autostash --autostash
+	test_pull_autostash 1 --autostash
 '
 
 test_expect_success 'pull --no-autostash & pull.rebase=true' '
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 132608879a..5883a6adc3 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -29,15 +29,19 @@ Testing basic merge operations/option parsing.
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-gpg.sh
 
-printf '%s\n' 1 2 3 4 5 6 7 8 9 >file
-printf '%s\n' '1 X' 2 3 4 5 6 7 8 9 >file.1
-printf '%s\n' 1 2 3 4 '5 X' 6 7 8 9 >file.5
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 X' >file.9
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 Y' >file.9y
-printf '%s\n' '1 X' 2 3 4 5 6 7 8 9 >result.1
-printf '%s\n' '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
-printf '%s\n' '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 Z' >result.9z
+test_write_lines 1 2 3 4 5 6 7 8 9 >file
+cp file file.orig
+test_write_lines '1 X' 2 3 4 5 6 7 8 9 >file.1
+test_write_lines 1 2 '3 X' 4 5 6 7 8 9 >file.3
+test_write_lines 1 2 3 4 '5 X' 6 7 8 9 >file.5
+test_write_lines 1 2 3 4 5 6 7 8 '9 X' >file.9
+test_write_lines 1 2 3 4 5 6 7 8 '9 Y' >file.9y
+test_write_lines '1 X' 2 3 4 5 6 7 8 9 >result.1
+test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
+test_write_lines '1 X' 2 3 4 5 6 7 8 '9 X' >result.1-9
+test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
+test_write_lines '1 X' 2 '3 X' 4 '5 X' 6 7 8 '9 X' >result.1-3-5-9
+test_write_lines 1 2 3 4 5 6 7 8 '9 Z' >result.9z
 
 create_merge_msgs () {
 	echo "Merge tag 'c2'" >msg.1-5 &&
@@ -81,7 +85,7 @@ verify_head () {
 }
 
 verify_parents () {
-	printf '%s\n' "$@" >parents.expected &&
+	test_write_lines "$@" >parents.expected &&
 	>parents.actual &&
 	i=1 &&
 	while test $i -le $#
@@ -95,7 +99,7 @@ verify_parents () {
 }
 
 verify_mergeheads () {
-	printf '%s\n' "$@" >mergehead.expected &&
+	test_write_lines "$@" >mergehead.expected &&
 	while read sha1 rest
 	do
 		git rev-parse $sha1
@@ -675,6 +679,134 @@ test_expect_success 'refresh the index before merging' '
 	git merge c3
 '
 
+test_expect_success 'merge with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git merge --autostash c2 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'merge with merge.autoStash' '
+	test_config merge.autoStash true &&
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git merge c2 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'fast-forward merge with --autostash' '
+	git reset --hard c0 &&
+	git merge-file file file.orig file.5 &&
+	git merge --autostash c1 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp result.1-5 file
+'
+
+test_expect_success 'octopus merge with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.3 &&
+	git merge --autostash c2 c3 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5-9 merge-result &&
+	test_cmp result.1-3-5-9 file
+'
+
+test_expect_success 'conflicted merge with --autostash, --abort restores stash' '
+	git reset --hard c3 &&
+	cp file.1 file &&
+	test_must_fail git merge --autostash c7 &&
+	git merge --abort 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp file.1 file
+'
+
+test_expect_success 'completed merge (git commit) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git commit 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'completed merge (git merge --continue) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git merge --continue 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'aborted merge (merge --abort) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git merge --abort 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'aborted merge (reset --hard) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git reset --hard 2>err &&
+	test_i18ngrep "Autostash exists; creating a new stash entry." err &&
+	git diff --exit-code
+'
+
+test_expect_success 'quit merge with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git diff HEAD >expect &&
+	git merge --quit 2>err &&
+	test_i18ngrep "Autostash exists; creating a new stash entry." err &&
+	git diff HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge with conflicted --autostash changes' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9y &&
+	git diff >expect &&
+	test_when_finished "test_might_fail git stash drop" &&
+	git merge --autostash c3 2>err &&
+	test_i18ngrep "Applying autostash resulted in conflicts." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-9 merge-result &&
+	git stash show -p >actual &&
+	test_cmp expect actual
+'
+
 cat >expected.branch <<\EOF
 Merge branch 'c5-branch' (early part)
 EOF