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-rwxr-xr-xcontrib/examples/git-checkout.sh302
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
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--- /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