scripts/git-branchmove

   1 #!/bin/bash
   2 #
   3 # Moves a branch to or from the current git tree to or from
   4 # another git tree
   5 #
   6 # usage:   git-branchmove get|put REMOTE PATTERN
   7
   8 set -e
   9 set -o posix
  10
  11 fail () { echo >&2 "git-branchmove: $*"; exit 16; }
  12 badusage () { fail "bad usage: $*"; }
  13
  14 if [ $# -lt 3 ]; then badusage "too few arguments"; fi
  15
  16 op="$1"; shift
  17 case "$op" in get|put) ;; *) badusage "unknown operation \`$op'"; esac
  18
  19 remote="$1"; shift
  20
  21 # Plan of attack:
  22 #  determine execute-sh runes for src and dst trees
  23 #  list affected branches on source
  24 #  check that source branches are not checked out
  25 #  list affected branches on destination and moan if any nonequal overlap
  26 #  transfer src->dst refs/heads/BRANCH:refs/heads/BRANCH
  27 #  transfer and merge reflog(s) xxx todo
  28 #  delete src refs
  29
  30 case "$remote" in
  31 *:*)    remoteurl="$remote" ;;
  32 [/.]*)  remoteurl="$remote" ;;
  33 *)      remoteurl="$(
  34                 git config remote."$remote".pushurl ||
  35                 git config remote."$remote".url ||
  36                 fail "no pushurl or url defined for remote $remote"
  37                 )"
  38 esac
  39
  40 remote_spec="$(perl -e '
  41     $_ = $ARGV[0];
  42     if (m#^ssh://([^:/]+)(?:\:(\w+))?#) {
  43         print "$'\''|ssh ";
  44         print " -p $3" if $2;
  45         print "$1\n";
  46     } elsif (m#^([-+_.0-9a-zA-Z\@]+):(?!//|:)#) {
  47         print "$'\''|ssh $1\n";
  48     } elsif (m#^[/.]#) {
  49         print "$&|sh -c $1\n";
  50     } else {
  51         die "git-branchmove: unsupported remote url \`$_'\''\n";
  52     }
  53 ' "$remoteurl")"
  54
  55 remote_path="${remote_spec%%|*}"
  56 remote_rune="${remote_spec#*|}"
  57
  58 case $op in
  59 get)
  60         src_rune="$remote_rune"
  61         src_path="$remote_path"
  62         dst_rune="sh -c"
  63         dst_path=.
  64         updatemsg="git-branchmove: moved to $remote ($remoteurl)"
  65         push_fetch=fetch
  66         ;;
  67 put)
  68         dst_rune="$remote_rune"
  69         dst_path="$remote_path"
  70         src_rune="sh -c"
  71         src_path=.
  72         updatemsg="git-branchmove; moved to `hostname -f` by `whoami`"
  73         push_fetch=push
  74         ;;
  75 esac
  76
  77 on_src () { $src_rune "set -e; cd $src_path; $*"; }
  78 on_dst () { $dst_rune "set -e; cd $dst_path; $*"; }
  79
  80
  81 #----- fetch the current refs from both sides -----
  82
  83 branch_pats=''
  84 for branch_pat in "$@"; do
  85         branch_pats+=" '[r]efs/heads/$branch_pat'"
  86 done
  87
  88 get_branches_rune='
  89         git for-each-ref --format="%(refname)=%(objectname)" '"$branch_pats"'
  90 '
  91
  92 src_branches=( $(
  93         on_src '
  94                 printf H
  95                 git symbolic-ref -q HEAD || test $? = 1
  96                 echo " "
  97                 '"$get_branches_rune"'
  98         '
  99 ))
 100
 101 src_head="${src_branches[0]}"
 102 unset src_branches[0]
 103 : "${src_branches[@]}"
 104
 105 case "$src_head" in
 106 H) ;; # already detached
 107 *)
 108         src_head="${src_head#H}"
 109         for check in "${src_branches[@]}"; do
 110                 case "$check" in
 111                 "$src_head"=*)
 112                         fail "would delete checked-out branch $src_head"
 113                         ;;
 114                 esac
 115         done
 116         ;;
 117 esac
 118
 119
 120 if [ "${#src_branches[@]}" = 0 ]; then
 121         echo >&2 "git-branchmove: nothing to do"
 122         exit 1
 123 fi
 124
 125 dst_branches=( $(on_dst "$get_branches_rune") )
 126 : "${dst_branches[@]}"
 127
 128
 129 #----- check for nonequal overlaps -----
 130
 131 ok=true
 132 for dst_check in "${dst_branches[@]}"; do
 133         dst_ref="${dst_check%=*}"
 134         for src_check in "${src_branches[@]}"; do
 135                 case "$src_check" in
 136                 "$dst_check")   ;;
 137                 "$dst_ref"=*)
 138                         ok=false
 139                         echo >&2 "src: $src_check   dst: $dst_check"
 140                         ;;
 141                 esac
 142         done
 143 done
 144
 145 $ok || fail "would overwrite some destination branch(es)"
 146
 147
 148 #----- do the transfer -----
 149
 150 refspecs=()
 151 for src_xfer in "${src_branches[@]}"; do
 152         src_ref="${src_xfer%=*}"
 153         refspecs+=("$src_ref:$src_ref")
 154 done
 155
 156 case "$op" in
 157 put)    git push "$remote" "${refspecs[@]}"     ;;
 158 get)    git fetch "$remote" "${refspecs[@]}"    ;;
 159 *)      fail "unknown $op ???"                  ;;
 160 esac
 161
 162
 163 #----- delete the refs on the source -----
 164
 165 (
 166         printf "%s\n" "$updatemsg"
 167         for src_rm in "${src_branches[@]}"; do printf "%s\n" "$src_rm"; done
 168 ) | on_src '
 169         read updatemsg
 170         while read src_rm; do
 171                 src_ref="${src_rm%=*}"
 172                 src_obj="${src_rm##*=}"
 173                 git update-ref -m "$updatemsg" -d "$src_ref" "$src_obj"
 174                 echo "move complete: $src_ref"
 175         done
 176 '
 177
 178 echo "moved ${#src_branches[@]} branches."