Merge branch 'jh/status-v2-porcelain'

Enhance "git status --porcelain" output by collecting more data on
the state of the index and the working tree files, which may
further be used to teach git-prompt (in contrib/) to make fewer
calls to git.

* jh/status-v2-porcelain:
  status: unit tests for --porcelain=v2
  test-lib-functions.sh: add lf_to_nul helper
  git-status.txt: describe --porcelain=v2 format
  status: print branch info with --porcelain=v2 --branch
  status: print per-file porcelain v2 status data
  status: collect per-file data for --porcelain=v2
  status: support --porcelain[=<version>]
  status: cleanup API to wt_status_print
  status: rename long-format print routines

3 files changed, 618 insertions, 0 deletions

diff --git a/t/t7060-wtstatus.sh b/t/t7060-wtstatus.sh
index 4d17363a92..53cf42fac1 100755
--- a/t/t7060-wtstatus.sh
+++ b/t/t7060-wtstatus.sh
@@ -232,4 +232,25 @@ test_expect_success 'status --branch with detached HEAD' '
 	test_i18ncmp expected actual
 '
 
+## Duplicate the above test and verify --porcelain=v1 arg parsing.
+test_expect_success 'status --porcelain=v1 --branch with detached HEAD' '
+	git reset --hard &&
+	git checkout master^0 &&
+	git status --branch --porcelain=v1 >actual &&
+	cat >expected <<-EOF &&
+	## HEAD (no branch)
+	?? .gitconfig
+	?? actual
+	?? expect
+	?? expected
+	?? mdconflict/
+	EOF
+	test_i18ncmp expected actual
+'
+
+## Verify parser error on invalid --porcelain argument.
+test_expect_success 'status --porcelain=bogus' '
+	test_must_fail git status --porcelain=bogus
+'
+
 test_done
diff --git a/t/t7064-wtstatus-pv2.sh b/t/t7064-wtstatus-pv2.sh
new file mode 100755
index 0000000000..3012a4d7c0
--- /dev/null
+++ b/t/t7064-wtstatus-pv2.sh
@@ -0,0 +1,593 @@
+#!/bin/sh
+
+test_description='git status --porcelain=v2
+
+This test exercises porcelain V2 output for git status.'
+
+
+. ./test-lib.sh
+
+
+test_expect_success setup '
+	test_tick &&
+	git config core.autocrlf false &&
+	echo x >file_x &&
+	echo y >file_y &&
+	echo z >file_z &&
+	mkdir dir1 &&
+	echo a >dir1/file_a &&
+	echo b >dir1/file_b
+'
+
+test_expect_success 'before initial commit, nothing added, only untracked' '
+	cat >expect <<-EOF &&
+	# branch.oid (initial)
+	# branch.head master
+	? actual
+	? dir1/
+	? expect
+	? file_x
+	? file_y
+	? file_z
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=normal >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'before initial commit, things added' '
+	git add file_x file_y file_z dir1 &&
+	OID_A=$(git hash-object -t blob -- dir1/file_a) &&
+	OID_B=$(git hash-object -t blob -- dir1/file_b) &&
+	OID_X=$(git hash-object -t blob -- file_x) &&
+	OID_Y=$(git hash-object -t blob -- file_y) &&
+	OID_Z=$(git hash-object -t blob -- file_z) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid (initial)
+	# branch.head master
+	1 A. N... 000000 100644 100644 $_z40 $OID_A dir1/file_a
+	1 A. N... 000000 100644 100644 $_z40 $OID_B dir1/file_b
+	1 A. N... 000000 100644 100644 $_z40 $OID_X file_x
+	1 A. N... 000000 100644 100644 $_z40 $OID_Y file_y
+	1 A. N... 000000 100644 100644 $_z40 $OID_Z file_z
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'before initial commit, things added (-z)' '
+	lf_to_nul >expect <<-EOF &&
+	# branch.oid (initial)
+	# branch.head master
+	1 A. N... 000000 100644 100644 $_z40 $OID_A dir1/file_a
+	1 A. N... 000000 100644 100644 $_z40 $OID_B dir1/file_b
+	1 A. N... 000000 100644 100644 $_z40 $OID_X file_x
+	1 A. N... 000000 100644 100644 $_z40 $OID_Y file_y
+	1 A. N... 000000 100644 100644 $_z40 $OID_Z file_z
+	? actual
+	? expect
+	EOF
+
+	git status -z --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'make first commit, comfirm HEAD oid and branch' '
+	git commit -m initial &&
+	H0=$(git rev-parse HEAD) &&
+	cat >expect <<-EOF &&
+	# branch.oid $H0
+	# branch.head master
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'after first commit, create unstaged changes' '
+	echo x >>file_x &&
+	OID_X1=$(git hash-object -t blob -- file_x) &&
+	rm file_z &&
+	H0=$(git rev-parse HEAD) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid $H0
+	# branch.head master
+	1 .M N... 100644 100644 100644 $OID_X $OID_X file_x
+	1 .D N... 100644 100644 000000 $OID_Z $OID_Z file_z
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'after first commit but omit untracked files and branch' '
+	cat >expect <<-EOF &&
+	1 .M N... 100644 100644 100644 $OID_X $OID_X file_x
+	1 .D N... 100644 100644 000000 $OID_Z $OID_Z file_z
+	EOF
+
+	git status --porcelain=v2 --untracked-files=no >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'after first commit, stage existing changes' '
+	git add file_x &&
+	git rm file_z &&
+	H0=$(git rev-parse HEAD) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid $H0
+	# branch.head master
+	1 M. N... 100644 100644 100644 $OID_X $OID_X1 file_x
+	1 D. N... 100644 000000 000000 $OID_Z $_z40 file_z
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rename causes 2 path lines' '
+	git mv file_y renamed_y &&
+	H0=$(git rev-parse HEAD) &&
+
+	q_to_tab >expect <<-EOF &&
+	# branch.oid $H0
+	# branch.head master
+	1 M. N... 100644 100644 100644 $OID_X $OID_X1 file_x
+	1 D. N... 100644 000000 000000 $OID_Z $_z40 file_z
+	2 R. N... 100644 100644 100644 $OID_Y $OID_Y R100 renamed_yQfile_y
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rename causes 2 path lines (-z)' '
+	H0=$(git rev-parse HEAD) &&
+
+	## Lines use NUL path separator and line terminator, so double transform here.
+	q_to_nul <<-EOF | lf_to_nul >expect &&
+	# branch.oid $H0
+	# branch.head master
+	1 M. N... 100644 100644 100644 $OID_X $OID_X1 file_x
+	1 D. N... 100644 000000 000000 $OID_Z $_z40 file_z
+	2 R. N... 100644 100644 100644 $OID_Y $OID_Y R100 renamed_yQfile_y
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all -z >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'make second commit, confirm clean and new HEAD oid' '
+	git commit -m second &&
+	H1=$(git rev-parse HEAD) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid $H1
+	# branch.head master
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'confirm ignored files are not printed' '
+	test_when_finished "rm -f x.ign .gitignore" &&
+	echo x.ign >.gitignore &&
+	echo "ignore me" >x.ign &&
+
+	cat >expect <<-EOF &&
+	? .gitignore
+	? actual
+	? expect
+	EOF
+
+	git status --porcelain=v2 --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ignored files are printed with --ignored' '
+	test_when_finished "rm -f x.ign .gitignore" &&
+	echo x.ign >.gitignore &&
+	echo "ignore me" >x.ign &&
+
+	cat >expect <<-EOF &&
+	? .gitignore
+	? actual
+	? expect
+	! x.ign
+	EOF
+
+	git status --porcelain=v2 --ignored --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'create and commit permanent ignore file' '
+	cat >.gitignore <<-EOF &&
+	actual*
+	expect*
+	EOF
+
+	git add .gitignore &&
+	git commit -m ignore_trash &&
+	H1=$(git rev-parse HEAD) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid $H1
+	# branch.head master
+	EOF
+
+	git status --porcelain=v2 --branch >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'verify --intent-to-add output' '
+	test_when_finished "git rm -f intent1.add intent2.add" &&
+	touch intent1.add &&
+	echo test >intent2.add &&
+
+	git add --intent-to-add intent1.add intent2.add &&
+
+	cat >expect <<-EOF &&
+	1 AM N... 000000 100644 100644 $_z40 $EMPTY_BLOB intent1.add
+	1 AM N... 000000 100644 100644 $_z40 $EMPTY_BLOB intent2.add
+	EOF
+
+	git status --porcelain=v2 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'verify AA (add-add) conflict' '
+	test_when_finished "git reset --hard" &&
+
+	git branch AA_A master &&
+	git checkout AA_A &&
+	echo "Branch AA_A" >conflict.txt &&
+	OID_AA_A=$(git hash-object -t blob -- conflict.txt) &&
+	git add conflict.txt &&
+	git commit -m "branch aa_a" &&
+
+	git branch AA_B master &&
+	git checkout AA_B &&
+	echo "Branch AA_B" >conflict.txt &&
+	OID_AA_B=$(git hash-object -t blob -- conflict.txt) &&
+	git add conflict.txt &&
+	git commit -m "branch aa_b" &&
+
+	git branch AA_M AA_B &&
+	git checkout AA_M &&
+	test_must_fail git merge AA_A &&
+
+	HM=$(git rev-parse HEAD) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid $HM
+	# branch.head AA_M
+	u AA N... 000000 100644 100644 100644 $_z40 $OID_AA_B $OID_AA_A conflict.txt
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'verify UU (edit-edit) conflict' '
+	test_when_finished "git reset --hard" &&
+
+	git branch UU_ANC master &&
+	git checkout UU_ANC &&
+	echo "Ancestor" >conflict.txt &&
+	OID_UU_ANC=$(git hash-object -t blob -- conflict.txt) &&
+	git add conflict.txt &&
+	git commit -m "UU_ANC" &&
+
+	git branch UU_A UU_ANC &&
+	git checkout UU_A &&
+	echo "Branch UU_A" >conflict.txt &&
+	OID_UU_A=$(git hash-object -t blob -- conflict.txt) &&
+	git add conflict.txt &&
+	git commit -m "branch uu_a" &&
+
+	git branch UU_B UU_ANC &&
+	git checkout UU_B &&
+	echo "Branch UU_B" >conflict.txt &&
+	OID_UU_B=$(git hash-object -t blob -- conflict.txt) &&
+	git add conflict.txt &&
+	git commit -m "branch uu_b" &&
+
+	git branch UU_M UU_B &&
+	git checkout UU_M &&
+	test_must_fail git merge UU_A &&
+
+	HM=$(git rev-parse HEAD) &&
+
+	cat >expect <<-EOF &&
+	# branch.oid $HM
+	# branch.head UU_M
+	u UU N... 100644 100644 100644 100644 $OID_UU_ANC $OID_UU_B $OID_UU_A conflict.txt
+	EOF
+
+	git status --porcelain=v2 --branch --untracked-files=all >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'verify upstream fields in branch header' '
+	git checkout master &&
+	test_when_finished "rm -rf sub_repo" &&
+	git clone . sub_repo &&
+	(
+		## Confirm local master tracks remote master.
+		cd sub_repo &&
+		HUF=$(git rev-parse HEAD) &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HUF
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual &&
+
+		## Test ahead/behind.
+		echo xyz >file_xyz &&
+		git add file_xyz &&
+		git commit -m xyz &&
+
+		HUF=$(git rev-parse HEAD) &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HUF
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +1 -0
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual &&
+
+		## Repeat the above but without --branch.
+		cat >expect <<-EOF &&
+		EOF
+
+		git status --porcelain=v2 --untracked-files=all >actual &&
+		test_cmp expect actual &&
+
+		## Test upstream-gone case. Fake this by pointing origin/master at
+		## a non-existing commit.
+		OLD=$(git rev-parse origin/master) &&
+		NEW=$_z40 &&
+		mv .git/packed-refs .git/old-packed-refs &&
+		sed "s/$OLD/$NEW/g" <.git/old-packed-refs >.git/packed-refs &&
+
+		HUF=$(git rev-parse HEAD) &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HUF
+		# branch.head master
+		# branch.upstream origin/master
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'create and add submodule, submodule appears clean (A. S...)' '
+	git checkout master &&
+	git clone . sub_repo &&
+	git clone . super_repo &&
+	(	cd super_repo &&
+		git submodule add ../sub_repo sub1 &&
+
+		## Confirm stage/add of clean submodule.
+		HMOD=$(git hash-object -t blob -- .gitmodules) &&
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$HSUP &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
+		1 A. S... 000000 160000 160000 $_z40 $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'untracked changes in added submodule (AM S..U)' '
+	(	cd super_repo &&
+		## create untracked file in the submodule.
+		(	cd sub1 &&
+			echo "xxxx" >file_in_sub
+		) &&
+
+		HMOD=$(git hash-object -t blob -- .gitmodules) &&
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$HSUP &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
+		1 AM S..U 000000 160000 160000 $_z40 $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'staged changes in added submodule (AM S.M.)' '
+	(	cd super_repo &&
+		## stage the changes in the submodule.
+		(	cd sub1 &&
+			git add file_in_sub
+		) &&
+
+		HMOD=$(git hash-object -t blob -- .gitmodules) &&
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$HSUP &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
+		1 AM S.M. 000000 160000 160000 $_z40 $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'staged and unstaged changes in added (AM S.M.)' '
+	(	cd super_repo &&
+		(	cd sub1 &&
+			## make additional unstaged changes (on the same file) in the submodule.
+			## This does not cause us to get S.MU (because the submodule does not report
+			## a "?" line for the unstaged changes).
+			echo "more changes" >>file_in_sub
+		) &&
+
+		HMOD=$(git hash-object -t blob -- .gitmodules) &&
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$HSUP &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
+		1 AM S.M. 000000 160000 160000 $_z40 $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'staged and untracked changes in added submodule (AM S.MU)' '
+	(	cd super_repo &&
+		(	cd sub1 &&
+			## stage new changes in tracked file.
+			git add file_in_sub &&
+			## create new untracked file.
+			echo "yyyy" >>another_file_in_sub
+		) &&
+
+		HMOD=$(git hash-object -t blob -- .gitmodules) &&
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$HSUP &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
+		1 AM S.MU 000000 160000 160000 $_z40 $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'commit within the submodule appears as new commit in super (AM SC..)' '
+	(	cd super_repo &&
+		(	cd sub1 &&
+			## Make a new commit in the submodule.
+			git add file_in_sub &&
+			rm -f another_file_in_sub &&
+			git commit -m "new commit"
+		) &&
+
+		HMOD=$(git hash-object -t blob -- .gitmodules) &&
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$HSUP &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +0 -0
+		1 A. N... 000000 100644 100644 $_z40 $HMOD .gitmodules
+		1 AM SC.. 000000 160000 160000 $_z40 $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'stage submodule in super and commit' '
+	(	cd super_repo &&
+		## Stage the new submodule commit in the super.
+		git add sub1 &&
+		## Commit the super so that the sub no longer appears as added.
+		git commit -m "super commit" &&
+
+		HSUP=$(git rev-parse HEAD) &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +1 -0
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'make unstaged changes in existing submodule (.M S.M.)' '
+	(	cd super_repo &&
+		(	cd sub1 &&
+			echo "zzzz" >>file_in_sub
+		) &&
+
+		HSUP=$(git rev-parse HEAD) &&
+		HSUB=$(cd sub1 && git rev-parse HEAD) &&
+
+		cat >expect <<-EOF &&
+		# branch.oid $HSUP
+		# branch.head master
+		# branch.upstream origin/master
+		# branch.ab +1 -0
+		1 .M S.M. 160000 160000 160000 $HSUB $HSUB sub1
+		EOF
+
+		git status --porcelain=v2 --branch --untracked-files=all >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_done
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 4f7eadb596..fdaeb3a96b 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -81,6 +81,10 @@ test_decode_color () {
 	'
 }
 
+lf_to_nul () {
+	perl -pe 'y/\012/\000/'
+}
+
 nul_to_q () {
 	perl -pe 'y/\000/Q/'
 }