Merge branch 'jl/submodule-add-by-name'

If you remove a submodule, in order to keep the repository so that
"git checkout" to an older commit in the superproject history can
resurrect the submodule, the real repository will stay in $GIT_DIR
of the superproject.  A later "git submodule add $path" to add a
different submodule at the same path will fail.  Diagnose this case
a bit better, and if the user really wants to add an unrelated
submodule at the same path, give the "--name" option to give it a
place in $GIT_DIR of the superproject that does not conflict with
the original submodule.

* jl/submodule-add-by-name:
  submodule add: Fail when .git/modules/<name> already exists unless forced
  Teach "git submodule add" the --name option

2 files changed, 76 insertions, 1 deletions

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 5397037491..de7d45352e 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -681,4 +681,79 @@ test_expect_success 'moving the superproject does not break submodules' '
 	)
 '
 
+test_expect_success 'submodule add --name allows to replace a submodule with another at the same path' '
+	(
+		cd addtest2 &&
+		(
+			cd repo &&
+			echo "$submodurl/repo" >expect &&
+			git config remote.origin.url >actual &&
+			test_cmp expect actual &&
+			echo "gitdir: ../.git/modules/repo" >expect &&
+			test_cmp expect .git
+		) &&
+		rm -rf repo &&
+		git rm repo &&
+		git submodule add -q --name repo_new "$submodurl/bare.git" repo >actual &&
+		test ! -s actual &&
+		echo "gitdir: ../.git/modules/submod" >expect &&
+		test_cmp expect submod/.git &&
+		(
+			cd repo &&
+			echo "$submodurl/bare.git" >expect &&
+			git config remote.origin.url >actual &&
+			test_cmp expect actual &&
+			echo "gitdir: ../.git/modules/repo_new" >expect &&
+			test_cmp expect .git
+		) &&
+		echo "repo" >expect &&
+		git config -f .gitmodules submodule.repo.path >actual &&
+		test_cmp expect actual &&
+		git config -f .gitmodules submodule.repo_new.path >actual &&
+		test_cmp expect actual&&
+		echo "$submodurl/repo" >expect &&
+		git config -f .gitmodules submodule.repo.url >actual &&
+		test_cmp expect actual &&
+		echo "$submodurl/bare.git" >expect &&
+		git config -f .gitmodules submodule.repo_new.url >actual &&
+		test_cmp expect actual &&
+		echo "$submodurl/repo" >expect &&
+		git config submodule.repo.url >actual &&
+		test_cmp expect actual &&
+		echo "$submodurl/bare.git" >expect &&
+		git config submodule.repo_new.url >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'submodule add with an existing name fails unless forced' '
+	(
+		cd addtest2 &&
+		rm -rf repo &&
+		git rm repo &&
+		test_must_fail git submodule add -q --name repo_new "$submodurl/repo.git" repo &&
+		test ! -d repo &&
+		echo "repo" >expect &&
+		git config -f .gitmodules submodule.repo_new.path >actual &&
+		test_cmp expect actual&&
+		echo "$submodurl/bare.git" >expect &&
+		git config -f .gitmodules submodule.repo_new.url >actual &&
+		test_cmp expect actual &&
+		echo "$submodurl/bare.git" >expect &&
+		git config submodule.repo_new.url >actual &&
+		test_cmp expect actual &&
+		git submodule add -f -q --name repo_new "$submodurl/repo.git" repo &&
+		test -d repo &&
+		echo "repo" >expect &&
+		git config -f .gitmodules submodule.repo_new.path >actual &&
+		test_cmp expect actual&&
+		echo "$submodurl/repo.git" >expect &&
+		git config -f .gitmodules submodule.repo_new.url >actual &&
+		test_cmp expect actual &&
+		echo "$submodurl/repo.git" >expect &&
+		git config submodule.repo_new.url >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_done
diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index 15426530e4..feaec6cdf4 100755
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -627,7 +627,7 @@ test_expect_success 'submodule add properly re-creates deeper level submodules'
 	(cd super &&
 	 git reset --hard master &&
 	 rm -rf deeper/ &&
-	 git submodule add ../submodule deeper/submodule
+	 git submodule add --force ../submodule deeper/submodule
 	)
 '