When on master, "git checkout -B master <commit>" is a more natural way to
say "git reset --keep <commit>", which was originally invented for the
exact purpose of moving to the named commit while keeping the local changes
around.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the error message when doing: "git branch @{-1}",
"git checkout -b @{-1}", or "git branch -m foo @{-1}"
* was: A branch named '@{-1}' already exists.
* now: A branch named 'bar' already exists.
Signed-off-by: Conrad Irwin <conrad.irwin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git branch -M <foo> <current-branch>" allows updating the current branch
which HEAD points, without the necessary house-keeping that git reset
normally does to make this operation sensible. It also leaves the reflog
in a confusing state (you would be warned when trying to read it).
"git checkout -B <current branch> <foo>" is also partly vulnerable to this
bug; due to inconsistent pre-flight checks it would perform half of its
task and then abort just before rewriting the branch. Again this
manifested itself as the index file getting out-of-sync with HEAD.
"git branch -f" already guarded against this problem, and aborts with
a fatal error.
Update "git branch -M", "git checkout -B" and "git branch -f" to share the
same check before allowing a branch to be created. These prevent you from
updating the current branch.
We considered suggesting the use of "git reset" in the failure message
but concluded that it was not possible to discern what the user was
actually trying to do.
Signed-off-by: Conrad Irwin <conrad.irwin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When create a new branch, we fed "refs/heads/<proposed name>" as a string
to get_sha1() and expected it to fail when a branch already exists.
The right way to check if a ref exists is to check with resolve_ref().
A naïve solution that might appear attractive but does not work is to
forbid slashes in get_describe_name() but that will not work. A describe
name is is in the form of "ANYTHING-g<short sha1>", and that ANYTHING part
comes from a original tag name used in the repository the user ran the
describe command. A sick user could have a confusing hierarchical tag
whose name is "refs/heads/foobar" (stored as refs/tags/refs/heads/foobar")
to generate a describe name "refs/heads/foobar-6-g02ac983", and we should
be able to use that name to refer to the object whose name is 02ac983.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ensure that strcmp() isn't called when head is null.
Previously we were getting segfaults when checkout -B was done from a
detached HEAD.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Internally, --track and --orphan still use the 'safe' -b, not -B.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
