Merge branch 'sb/submodule-embed-gitdir'

A new submodule helper "git submodule embedgitdirs" to make it
easier to move embedded .git/ directory for submodules in a
superproject to .git/modules/ (and point the latter with the former
that is turned into a "gitdir:" file) has been added.

* sb/submodule-embed-gitdir:
  worktree: initialize return value for submodule_uses_worktrees
  submodule: add absorb-git-dir function
  move connect_work_tree_and_git_dir to dir.h
  worktree: check if a submodule uses worktrees
  test-lib-functions.sh: teach test_commit -C <dir>
  submodule helper: support super prefix
  submodule: use absolute path for computing relative path connecting

2 files changed, 116 insertions, 5 deletions

diff --git a/t/t7412-submodule-absorbgitdirs.sh b/t/t7412-submodule-absorbgitdirs.sh
new file mode 100755
index 0000000000..1c47780e2b
--- /dev/null
+++ b/t/t7412-submodule-absorbgitdirs.sh
@@ -0,0 +1,101 @@
+#!/bin/sh
+
+test_description='Test submodule absorbgitdirs
+
+This test verifies that `git submodue absorbgitdirs` moves a submodules git
+directory into the superproject.
+'
+
+. ./test-lib.sh
+
+test_expect_success 'setup a real submodule' '
+	git init sub1 &&
+	test_commit -C sub1 first &&
+	git submodule add ./sub1 &&
+	test_tick &&
+	git commit -m superproject
+'
+
+test_expect_success 'absorb the git dir' '
+	>expect.1 &&
+	>expect.2 &&
+	>actual.1 &&
+	>actual.2 &&
+	git status >expect.1 &&
+	git -C sub1 rev-parse HEAD >expect.2 &&
+	git submodule absorbgitdirs &&
+	git fsck &&
+	test -f sub1/.git &&
+	test -d .git/modules/sub1 &&
+	git status >actual.1 &&
+	git -C sub1 rev-parse HEAD >actual.2 &&
+	test_cmp expect.1 actual.1 &&
+	test_cmp expect.2 actual.2
+'
+
+test_expect_success 'absorbing does not fail for deinitalized submodules' '
+	test_when_finished "git submodule update --init" &&
+	git submodule deinit --all &&
+	git submodule absorbgitdirs &&
+	test -d .git/modules/sub1 &&
+	test -d sub1 &&
+	! test -e sub1/.git
+'
+
+test_expect_success 'setup nested submodule' '
+	git init sub1/nested &&
+	test_commit -C sub1/nested first_nested &&
+	git -C sub1 submodule add ./nested &&
+	test_tick &&
+	git -C sub1 commit -m "add nested" &&
+	git add sub1 &&
+	git commit -m "sub1 to include nested submodule"
+'
+
+test_expect_success 'absorb the git dir in a nested submodule' '
+	git status >expect.1 &&
+	git -C sub1/nested rev-parse HEAD >expect.2 &&
+	git submodule absorbgitdirs &&
+	test -f sub1/nested/.git &&
+	test -d .git/modules/sub1/modules/nested &&
+	git status >actual.1 &&
+	git -C sub1/nested rev-parse HEAD >actual.2 &&
+	test_cmp expect.1 actual.1 &&
+	test_cmp expect.2 actual.2
+'
+
+test_expect_success 'setup a gitlink with missing .gitmodules entry' '
+	git init sub2 &&
+	test_commit -C sub2 first &&
+	git add sub2 &&
+	git commit -m superproject
+'
+
+test_expect_success 'absorbing the git dir fails for incomplete submodules' '
+	git status >expect.1 &&
+	git -C sub2 rev-parse HEAD >expect.2 &&
+	test_must_fail git submodule absorbgitdirs &&
+	git -C sub2 fsck &&
+	test -d sub2/.git &&
+	git status >actual &&
+	git -C sub2 rev-parse HEAD >actual.2 &&
+	test_cmp expect.1 actual.1 &&
+	test_cmp expect.2 actual.2
+'
+
+test_expect_success 'setup a submodule with multiple worktrees' '
+	# first create another unembedded git dir in a new submodule
+	git init sub3 &&
+	test_commit -C sub3 first &&
+	git submodule add ./sub3 &&
+	test_tick &&
+	git commit -m "add another submodule" &&
+	git -C sub3 worktree add ../sub3_second_work_tree
+'
+
+test_expect_success 'absorbing fails for a submodule with multiple worktrees' '
+	test_must_fail git submodule absorbgitdirs sub3 2>error &&
+	test_i18ngrep "not supported" error
+'
+
+test_done
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index adab7f51f4..bd357704cc 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -157,16 +157,21 @@ debug () {
 	 GIT_TEST_GDB=1 "$@"
 }
 
-# Call test_commit with the arguments "<message> [<file> [<contents> [<tag>]]]"
+# Call test_commit with the arguments
+# [-C <directory>] <message> [<file> [<contents> [<tag>]]]"
 #
 # This will commit a file with the given contents and the given commit
 # message, and tag the resulting commit with the given tag name.
 #
 # <file>, <contents>, and <tag> all default to <message>.
+#
+# If the first argument is "-C", the second argument is used as a path for
+# the git invocations.
 
 test_commit () {
 	notick= &&
 	signoff= &&
+	indir= &&
 	while test $# != 0
 	do
 		case "$1" in
@@ -176,21 +181,26 @@ test_commit () {
 		--signoff)
 			signoff="$1"
 			;;
+		-C)
+			indir="$2"
+			shift
+			;;
 		*)
 			break
 			;;
 		esac
 		shift
 	done &&
+	indir=${indir:+"$indir"/} &&
 	file=${2:-"$1.t"} &&
-	echo "${3-$1}" > "$file" &&
-	git add "$file" &&
+	echo "${3-$1}" > "$indir$file" &&
+	git ${indir:+ -C "$indir"} add "$file" &&
 	if test -z "$notick"
 	then
 		test_tick
 	fi &&
-	git commit $signoff -m "$1" &&
-	git tag "${4:-$1}"
+	git ${indir:+ -C "$indir"} commit $signoff -m "$1" &&
+	git ${indir:+ -C "$indir"} tag "${4:-$1}"
 }
 
 # Call test_merge with the arguments "<message> <commit>", where <commit>