git checkout: do not allow switching to a tree-ish that is not a commit

"git checkout -b newbranch $commit^{tree}" mistakenly created a new branch
rooted at the current HEAD, because in that case, the two structure fields
used to see if the command was invoked without any argument (hence it
needs to default to checking out the HEAD) were populated incorrectly.

Upon seeing a command line argument that we took as a rev, we should store
that string in new.name, even if that does not name a commit.  This will
correctly trigger the existing safety logic.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Daniel Barkalow <barkalow@iabervon.org>
This commit is contained in:
Junio C Hamano 2009-01-03 04:07:32 -08:00
parent 27c03aafdf
commit 3442ea4a75
2 changed files with 5 additions and 1 deletions

View file

@ -515,8 +515,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
argv++;
argc--;
new.name = arg;
if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
new.name = arg;
setup_branch_path(&new);
if (resolve_ref(new.path, rev, 1, NULL))
new.commit = lookup_commit_reference(rev);

View file

@ -10,6 +10,10 @@ test_expect_success 'setup' '
git commit -m initial
'
test_expect_success 'checkout should not start branch from a tree' '
test_must_fail git checkout -b newbranch master^{tree}
'
test_expect_success 'checkout master from invalid HEAD' '
echo 0000000000000000000000000000000000000000 >.git/HEAD &&
git checkout master --