Andrew's git - gitweb.git/blob

   1#!/bin/sh
   2
   3USAGE='[-f] [-b <new_branch>] [<branch>] [<paths>...]'
   4. git-sh-setup
   5
   6old=$(git-rev-parse HEAD)
   7new=
   8force=
   9branch=
  10newbranch=
  11while [ "$#" != "0" ]; do
  12    arg="$1"
  13    shift
  14    case "$arg" in
  15        "-b")
  16                newbranch="$1"
  17                shift
  18                [ -z "$newbranch" ] &&
  19                        die "git checkout: -b needs a branch name"
  20                [ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
  21                        die "git checkout: branch $newbranch already exists"
  22                git-check-ref-format "heads/$newbranch" ||
  23                        die "we do not like '$newbranch' as a branch name."
  24                ;;
  25        "-f")
  26                force=1
  27                ;;
  28        --)
  29                break
  30                ;;
  31        -*)
  32                usage
  33                ;;
  34        *)
  35                if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
  36                then
  37                        if [ -z "$rev" ]; then
  38                                echo "unknown flag $arg"
  39                                exit 1
  40                        fi
  41                        new="$rev"
  42                        if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
  43                                branch="$arg"
  44                        fi
  45                elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
  46                then
  47                        # checking out selected paths from a tree-ish.
  48                        new="$rev"
  49                        branch=
  50                else
  51                        new=
  52                        branch=
  53                        set x "$arg" "$@"
  54                        shift
  55                fi
  56                break
  57                ;;
  58    esac
  59done
  60
  61# The behaviour of the command with and without explicit path
  62# parameters is quite different.
  63#
  64# Without paths, we are checking out everything in the work tree,
  65# possibly switching branches.  This is the traditional behaviour.
  66#
  67# With paths, we are _never_ switching branch, but checking out
  68# the named paths from either index (when no rev is given),
  69# or the named tree-ish (when rev is given).
  70
  71if test "$#" -ge 1
  72then
  73        if test '' != "$newbranch$force"
  74        then
  75                die "updating paths and switching branches or forcing are incompatible."
  76        fi
  77        if test '' != "$new"
  78        then
  79                # from a specific tree-ish; note that this is for
  80                # rescuing paths and is never meant to remove what
  81                # is not in the named tree-ish.
  82                git-ls-tree -r "$new" "$@" |
  83                git-update-index --index-info || exit $?
  84        fi
  85        git-checkout-index -f -u -- "$@"
  86        exit $?
  87else
  88        # Make sure we did not fall back on $arg^{tree} codepath
  89        # since we are not checking out from an arbitrary tree-ish,
  90        # but switching branches.
  91        if test '' != "$new"
  92        then
  93                git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
  94                die "Cannot switch branch to a non-commit."
  95        fi
  96fi
  97
  98[ -z "$new" ] && new=$old
  99
 100# If we don't have an old branch that we're switching to,
 101# and we don't have a new branch name for the target we
 102# are switching to, then we'd better just be checking out
 103# what we already had
 104
 105[ -z "$branch$newbranch" ] &&
 106        [ "$new" != "$old" ] &&
 107        die "git checkout: you need to specify a new branch name"
 108
 109if [ "$force" ]
 110then
 111    git-read-tree --reset $new &&
 112        git-checkout-index -q -f -u -a
 113else
 114    git-update-index --refresh >/dev/null
 115    git-read-tree -m -u $old $new
 116fi
 117
 118# 
 119# Switch the HEAD pointer to the new branch if it we
 120# checked out a branch head, and remove any potential
 121# old MERGE_HEAD's (subsequent commits will clearly not
 122# be based on them, since we re-set the index)
 123#
 124if [ "$?" -eq 0 ]; then
 125        if [ "$newbranch" ]; then
 126                leading=`expr "refs/heads/$newbranch" : '\(.*\)/'` &&
 127                mkdir -p "$GIT_DIR/$leading" &&
 128                echo $new >"$GIT_DIR/refs/heads/$newbranch" || exit
 129                branch="$newbranch"
 130        fi
 131        [ "$branch" ] &&
 132        GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch"
 133        rm -f "$GIT_DIR/MERGE_HEAD"
 134else
 135        exit 1
 136fi