By definition, a detached HEAD state is tentative and there is no
configured "upstream" that it always wants to integrate with. But
if you detach from a branch that is behind its upstream, e.g.,
$ git checkout -t -b main origin/main
$ git checkout main
$ git reset --hard HEAD^
$ git checkout --detach main
you'd see "you are behind your upstream origin/main". This does not
happen when you replace the last step in the above with any of these
$ git checkout HEAD^0
$ git checkout --detach HEAD
$ git checkout --detach origin/main
Before 32669671 (checkout: introduce --detach synonym for "git
checkout foo^{commit}", 2011-02-08) introduced the "--detach"
option, the rule to decide if we show the tracking information
used to be:
If --quiet is not given, and if the given branch name is a real
local branch (i.e. the one we can compute the file path under
.git/, like 'refs/heads/master' or "HEAD" which stand for the
name of the current branch", then give the tracking information.
to exclude things like "git checkout master^0" (which was the
official way to detach HEAD at the commit before that commit) and
"git checkout origin/master^0" from showing tracking information,
but still do show the tracking information for the current branch
for "git checkout HEAD". The introduction of an explicit option
"--detach" broke this subtley. The new rule should have been
If --quiet is given, do not bother with tracking info.
If --detach is given, do not bother with tracking info.
Otherwise, if we know that the branch name given is a real local
branch, or if we were given "HEAD" and "HEAD" is not detached,
then attempt to show the tracking info.
but it allowed "git checkout --detach master" to also show the
tracking info by mistake. Let's tighten the rule to fix this.
Reported-by: mirth hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
b9f2e1a684