submodule add: Fail when .git/modules/<name> already exists unless forced

When adding a new submodule it can happen that .git/modules/<name> already
contains a submodule repo, e.g. when a submodule is removed from the work
tree and another submodule is added at the same path. But then the work
tree of the submodule will be populated using the existing repository and
not the one the user provided, which results in an incorrect work tree. On
the other hand the user might reactivate a submodule removed earlier, then
reusing that .git directory is the Right Thing to do.

As git can't decide what is the case, error out and tell the user she
should use either use a different name for the submodule with the "--name"
option or can reuse the .git directory for the newly added submodule by
providing the --force option (which only makes sense when the upstream
matches, so the error message lists all remotes of .git/modules/<name>).

In one test in t7406 the --force option had to be added to "git submodule
add", as that test re-adds a formerly removed submodule.

Reported-by: Jonathan Johnson <me@jondavidjohn.com>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-submodule.sh b/git-submodule.sh
index 22febb104c62fdeea62d8d1f1463e64cc5764489..e8112c8d1a79d3ad654041d1e61d168fb3992b06 100755 (executable)
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -359,7 +359,20 @@ Use -f if you really want to add it." >&2
                fi
 
        else
-
+               if test -d ".git/modules/$sm_name"
+               then
+                       if test -z "$force"
+                       then
+                               echo >&2 "$(eval_gettext "A git directory for '\$sm_name' is found locally with remote(s):")"
+                               GIT_DIR=".git/modules/$sm_name" GIT_WORK_TREE=. git remote -v | grep '(fetch)' | sed -e s,^,"  ", -e s,' (fetch)',, >&2
+                               echo >&2 "$(eval_gettext "If you want to reuse this local git directory instead of cloning again from")"
+                               echo >&2 "  $realrepo"
+                               echo >&2 "$(eval_gettext "use the '--force' option. If the local git directory is not the correct repo")"
+                               die "$(eval_gettext "or you are unsure what this means choose another name with the '--name' option.")"
+                       else
+                               echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
+                       fi
+               fi
                module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" || exit
                (
                        clear_local_git_env

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 78bf73938ec84a292928696126737bba32961583..f1a94f7ca128655de04df01a8b3479b0b95bc18a 100755 (executable)
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -726,4 +726,34 @@ test_expect_success 'submodule add --name allows to replace a submodule with ano
        )
 '
 
+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 15426530e49ef2e42cda2528f4a72a784eb40cd9..feaec6cdf4b8c7eac348ea1de61887c93c69244d 100755 (executable)
--- 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
        )
 '