clone: support atomic operation with --separate-git-dir

Since b57fb80a7d (init, clone: support --separate-git-dir for .git file)
git clone supports the --separate-git-dir option to create the git dir
outside the work tree. But when that option is used, the git dir won't be
deleted in case the clone fails like it would be without this option. This
makes clone lose its atomicity as in case of a failure a partly set up git
dir is left behind. A real world example where this leads to problems is
when "git submodule update" fails to clone a submodule and later calls to
"git submodule update" stumble over the partially set up git dir and try
to revive the submodule from there, which then fails with a not very user
friendly error message.

Fix that by updating the junk_git_dir variable (used to remember if and
what git dir should be removed in case of failure) to the new value given
with the --seperate-git-dir option. Also add a test for this to t5600 (and
while at it fix the former last test to not cd into a directory to test
for its existence but use "test -d" instead).

Reported-by: Manlio Perillo <manlio.perillo@gmail.com>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/clone.c b/builtin/clone.c
index 097beca3ab4675be9fb324d6624be92b5330c816..b054313ab659605b5902e68bdb6ff364c3333e5e 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -471,8 +471,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
                die("could not create leading directories of '%s'", git_dir);
 
        set_git_dir_init(git_dir, real_git_dir, 0);
-       if (real_git_dir)
+       if (real_git_dir) {
                git_dir = real_git_dir;
+               junk_git_dir = real_git_dir;
+       }
 
        if (0 <= option_verbosity)
                printf("Cloning into %s%s...\n",

diff --git a/t/t5600-clone-fail-cleanup.sh b/t/t5600-clone-fail-cleanup.sh
index ee06d2864949de71b000402fda4378c9b483fe72..4435693bb2ca48d053003c87fccd8f8612d8b4a9 100755 (executable)
--- a/t/t5600-clone-fail-cleanup.sh
+++ b/t/t5600-clone-fail-cleanup.sh
@@ -37,6 +37,16 @@ test_expect_success \
 
 test_expect_success \
     'successful clone must leave the directory' \
-    'cd bar'
+    'test -d bar'
+
+test_expect_success 'failed clone --separate-git-dir should not leave any directories' '
+       mkdir foo/.git/objects.bak/ &&
+       mv foo/.git/objects/* foo/.git/objects.bak/ &&
+       test_must_fail git clone --separate-git-dir gitdir foo worktree &&
+       test_must_fail test -e gitdir &&
+       test_must_fail test -e worktree &&
+       mv foo/.git/objects.bak/* foo/.git/objects/ &&
+       rmdir foo/.git/objects.bak
+'
 
 test_done