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Diffstat (limited to 'contrib/examples/git-checkout.sh')
| -rwxr-xr-x | contrib/examples/git-checkout.sh | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/contrib/examples/git-checkout.sh b/contrib/examples/git-checkout.sh new file mode 100755 index 0000000000..683cae7c3f --- /dev/null +++ b/contrib/examples/git-checkout.sh @@ -0,0 +1,302 @@ +#!/bin/sh + +OPTIONS_KEEPDASHDASH=t +OPTIONS_SPEC="\ +git-checkout [options] [<branch>] [<paths>...] +-- +b= create a new branch started at <branch> +l create the new branch's reflog +track arrange that the new branch tracks the remote branch +f proceed even if the index or working tree is not HEAD +m merge local modifications into the new branch +q,quiet be quiet +" +SUBDIRECTORY_OK=Sometimes +. git-sh-setup +require_work_tree + +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= +branch= +track= +newbranch= +newbranch_log= +merge= +quiet= +v=-v +LF=' +' + +while test $# != 0; do + case "$1" in + -b) + shift + newbranch="$1" + [ -z "$newbranch" ] && + die "git checkout: -b needs a branch name" + git show-ref --verify --quiet -- "refs/heads/$newbranch" && + die "git checkout: branch $newbranch already exists" + git check-ref-format "heads/$newbranch" || + die "git checkout: we do not like '$newbranch' as a branch name." + ;; + -l) + newbranch_log=-l + ;; + --track|--no-track) + track="$1" + ;; + -f) + force=1 + ;; + -m) + merge=1 + ;; + -q|--quiet) + quiet=1 + v= + ;; + --) + shift + break + ;; + *) + usage + ;; + esac + shift +done + +arg="$1" +rev=$(git rev-parse --verify "$arg" 2>/dev/null) +if rev=$(git rev-parse --verify "$rev^0" 2>/dev/null) +then + [ -z "$rev" ] && die "unknown flag $arg" + new_name="$arg" + if git show-ref --verify --quiet -- "refs/heads/$arg" + then + rev=$(git rev-parse --verify "refs/heads/$arg^0") + branch="$arg" + fi + new="$rev" + shift +elif rev=$(git rev-parse --verify "$rev^{tree}" 2>/dev/null) +then + # checking out selected paths from a tree-ish. + new="$rev" + new_name="$rev^{tree}" + shift +fi +[ "$1" = "--" ] && shift + +case "$newbranch,$track" in +,--*) + die "git checkout: --track and --no-track require -b" +esac + +case "$force$merge" in +11) + die "git checkout: -f and -m are incompatible" +esac + +# The behaviour of the command with and without explicit path +# parameters is quite different. +# +# Without paths, we are checking out everything in the work tree, +# possibly switching branches. This is the traditional behaviour. +# +# With paths, we are _never_ switching branch, but checking out +# the named paths from either index (when no rev is given), +# or the named tree-ish (when rev is given). + +if test "$#" -ge 1 +then + hint= + if test "$#" -eq 1 + then + hint=" +Did you intend to checkout '$@' which can not be resolved as commit?" + fi + if test '' != "$newbranch$force$merge" + then + die "git checkout: updating paths is incompatible with switching branches/forcing$hint" + fi + if test '' != "$new" + then + # from a specific tree-ish; note that this is for + # rescuing paths and is never meant to remove what + # is not in the named tree-ish. + git ls-tree --full-name -r "$new" "$@" | + git update-index --index-info || exit $? + fi + + # Make sure the request is about existing paths. + git ls-files --full-name --error-unmatch -- "$@" >/dev/null || exit + git ls-files --full-name -- "$@" | + (cd_to_toplevel && git checkout-index -f -u --stdin) + + # Run a post-checkout hook -- the HEAD does not change so the + # current HEAD is passed in for both args + if test -x "$GIT_DIR"/hooks/post-checkout; then + "$GIT_DIR"/hooks/post-checkout $old $old 0 + fi + + exit $? +else + # Make sure we did not fall back on $arg^{tree} codepath + # since we are not checking out from an arbitrary tree-ish, + # but switching branches. + if test '' != "$new" + then + git rev-parse --verify "$new^{commit}" >/dev/null 2>&1 || + die "Cannot switch branch to a non-commit." + fi +fi + +# We are switching branches and checking out trees, so +# we *NEED* to be at the toplevel. +cd_to_toplevel + +[ -z "$new" ] && new=$old && new_name="$old_name" + +# 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 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" or "git checkout -f" to detach HEAD. + +detached= +detach_warn= + +describe_detached_head () { + test -n "$quiet" || { + printf >&2 "$1 " + GIT_PAGER= git log >&2 -1 --pretty=oneline --abbrev-commit "$2" -- + } +} + +if test -z "$branch$newbranch" && test "$new_name" != "$old_name" +then + detached="$new" + if test -n "$oldbranch" && test -z "$quiet" + then + detach_warn="Note: moving to \"$new_name\" which isn't a local branch +If you want to create a new branch from this checkout, you may do so +(now or later) by using -b with the checkout command again. Example: + git checkout -b <new_branch_name>" + fi +elif test -z "$oldbranch" && test "$new" != "$old" +then + describe_detached_head 'Previous HEAD position was' "$old" +fi + +if [ "X$old" = X ] +then + if test -z "$quiet" + then + echo >&2 "warning: You appear to be on a branch yet to be born." + echo >&2 "warning: Forcing checkout of $new_name." + fi + force=1 +fi + +if [ "$force" ] +then + git read-tree $v --reset -u $new +else + git update-index --refresh >/dev/null + git read-tree $v -m -u --exclude-per-directory=.gitignore $old $new || ( + case "$merge,$v" in + ,*) + exit 1 ;; + 1,) + ;; # quiet + *) + echo >&2 "Falling back to 3-way merge..." ;; + esac + + # Match the index to the working tree, and do a three-way. + git diff-files --name-only | git update-index --remove --stdin && + work=$(git write-tree) && + git read-tree $v --reset -u $new || exit + + eval GITHEAD_$new='${new_name:-${branch:-$new}}' && + eval GITHEAD_$work=local && + export GITHEAD_$new GITHEAD_$work && + git merge-recursive $old -- $new $work + + # Do not register the cleanly merged paths in the index yet. + # this is not a real merge before committing, but just carrying + # the working tree changes along. + unmerged=$(git ls-files -u) + git read-tree $v --reset $new + case "$unmerged" in + '') ;; + *) + ( + z40=0000000000000000000000000000000000000000 + echo "$unmerged" | + sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /" + echo "$unmerged" + ) | git update-index --index-info + ;; + esac + exit 0 + ) + saved_err=$? + if test "$saved_err" = 0 && test -z "$quiet" + then + git diff-index --name-status "$new" + fi + (exit $saved_err) +fi + +# +# Switch the HEAD pointer to the new branch if we +# checked out a branch head, and remove any potential +# old MERGE_HEAD's (subsequent commits will clearly not +# be based on them, since we re-set the index) +# +if [ "$?" -eq 0 ]; then + if [ "$newbranch" ]; then + git branch $track $newbranch_log "$newbranch" "$new_name" || exit + branch="$newbranch" + fi + if test -n "$branch" + then + old_branch_name=$(expr "z$oldbranch" : 'zrefs/heads/\(.*\)') + GIT_DIR="$GIT_DIR" git symbolic-ref -m "checkout: moving from ${old_branch_name:-$old} to $branch" HEAD "refs/heads/$branch" + if test -n "$quiet" + then + true # nothing + elif test "refs/heads/$branch" = "$oldbranch" + then + echo >&2 "Already on branch \"$branch\"" + else + echo >&2 "Switched to${newbranch:+ a new} branch \"$branch\"" + fi + elif test -n "$detached" + then + old_branch_name=$(expr "z$oldbranch" : 'zrefs/heads/\(.*\)') + git update-ref --no-deref -m "checkout: moving from ${old_branch_name:-$old} to $arg" HEAD "$detached" || + die "Cannot detach HEAD" + if test -n "$detach_warn" + then + echo >&2 "$detach_warn" + fi + describe_detached_head 'HEAD is now at' HEAD + fi + rm -f "$GIT_DIR/MERGE_HEAD" +else + exit 1 +fi + +# Run a post-checkout hook +if test -x "$GIT_DIR"/hooks/post-checkout; then + "$GIT_DIR"/hooks/post-checkout $old $new 1 +fi |