diff options
Diffstat (limited to 'git-checkout.sh')
| -rwxr-xr-x | git-checkout.sh | 74 |
1 files changed, 60 insertions, 14 deletions
diff --git a/git-checkout.sh b/git-checkout.sh index 92ec069a3..8f4356d49 100755 --- a/git-checkout.sh +++ b/git-checkout.sh @@ -6,6 +6,7 @@ SUBDIRECTORY_OK=Sometimes old_name=HEAD old=$(git-rev-parse --verify $old_name 2>/dev/null) +oldbranch=$(git-symbolic-ref $old_name 2>/dev/null) new= new_name= force= @@ -13,6 +14,8 @@ branch= newbranch= newbranch_log= merge= +LF=' +' while [ "$#" != "0" ]; do arg="$1" shift @@ -50,7 +53,7 @@ while [ "$#" != "0" ]; do exit 1 fi new="$rev" - new_name="$arg^0" + new_name="$arg" if git-show-ref --verify --quiet -- "refs/heads/$arg" then branch="$arg" @@ -139,23 +142,49 @@ fi [ -z "$new" ] && new=$old && new_name="$old_name" -# If we don't have an old branch that we're switching to, +# If we don't have an existing branch that we're switching to, # and we don't have a new branch name for the target we -# are switching to, then we'd better just be checking out -# what we already had +# are switching to, then we are detaching our HEAD from any +# branch. However, if "git checkout HEAD" detaches the HEAD +# from the current branch, even though that may be logically +# correct, it feels somewhat funny. More importantly, we do not +# want "git checkout" nor "git checkout -f" to detach HEAD. -[ -z "$branch$newbranch" ] && - [ "$new" != "$old" ] && - die "git checkout: provided reference cannot be checked out directly +detached= +detach_warn= - You need -b to associate a new branch with the wanted checkout. Example: - git checkout -b <new_branch_name> $arg -" +if test -z "$branch$newbranch" && test "$new" != "$old" +then + detached="$new" + if test -n "$oldbranch" + then + detach_warn="warning: you are not on ANY branch anymore. +If you meant to create a new branch from the commit, you need -b to +associate a new branch with the wanted checkout. Example: + git checkout -b <new_branch_name> $arg" + fi +elif test -z "$oldbranch" && test -n "$branch" +then + # Coming back... + if test -z "$force" + then + git show-ref -d -s | grep "$old" >/dev/null || { + echo >&2 \ +"You are not on any branch and switching to branch '$new_name' +may lose your changes. At this point, you can do one of two things: + (1) Decide it is Ok and say 'git checkout -f $new_name'; + (2) Start a new branch from the current commit, by saying + 'git checkout -b <branch-name>'. +Leaving your HEAD detached; not switching to branch '$new_name'." + exit 1; + } + fi +fi if [ "X$old" = X ] then - echo "warning: You do not appear to currently be on a branch." >&2 - echo "warning: Forcing checkout of $new_name." >&2 + echo >&2 "warning: You appear to be on a branch yet to be born." + echo >&2 "warning: Forcing checkout of $new_name." force=1 fi @@ -226,8 +255,25 @@ if [ "$?" -eq 0 ]; then git-update-ref -m "checkout: Created from $new_name" "refs/heads/$newbranch" $new || exit branch="$newbranch" fi - [ "$branch" ] && - GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch" + if test -n "$branch" + then + GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch" + elif test -n "$detached" + then + # NEEDSWORK: we would want a command to detach the HEAD + # atomically, instead of this handcrafted command sequence. + # Perhaps: + # git update-ref --detach HEAD $new + # or something like that... + # + echo "$detached" >"$GIT_DIR/HEAD.new" && + mv "$GIT_DIR/HEAD.new" "$GIT_DIR/HEAD" || + die "Cannot detach HEAD" + if test -n "$detach_warn" + then + echo >&2 "$detach_warn" + fi + fi rm -f "$GIT_DIR/MERGE_HEAD" else exit 1 |