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 $remote"
  37                 )"
  38         remotename="$remote"
  39 esac
  40
  41 remote_spec="$(perl -e '
  42     $_ = $ARGV[0];
  43     if (m#^ssh://([^:/]+)(?:\:(\w+))?#) {
  44         print "$'\''|ssh ";
  45         print " -p $3" if $2;
  46         print "$1\n";
  47     } elsif (m#^([-+_.0-9a-zA-Z\@]+):(?!//|:)#) {
  48         print "$'\''|ssh $1\n";
  49     } elsif (m#^[/.]#) {
  50         print "$_|sh -c $1\n";
  51     } else {
  52         die "git-branchmove: unsupported remote url \`$_'\''\n";
  53     }
  54 ' "$remoteurl")"
  55
  56 remote_path="${remote_spec%%|*}"
  57 remote_rune="${remote_spec#*|}"
  58
  59 case $op in
  60 get)
  61         src_rune="$remote_rune"
  62         src_path="$remote_path"
  63         dst_rune="sh -c"
  64         dst_path=.
  65         updatemsg="git-branchmove: moved to $remote ($remoteurl)"
  66         push_fetch=fetch
  67         ;;
  68 put)
  69         dst_rune="$remote_rune"
  70         dst_path="$remote_path"
  71         src_rune="sh -c"
  72         src_path=.
  73         updatemsg="git-branchmove; moved to `hostname -f` by `whoami`"
  74         push_fetch=push
  75         ;;
  76 esac
  77
  78 on_src () { $src_rune "set -e; cd $src_path; $*"; }
  79 on_dst () { $dst_rune "set -e; cd $dst_path; $*"; }
  80
  81
  82 #----- fetch the current refs from both sides -----
  83
  84 branch_pats=''
  85 for branch_pat in "$@"; do
  86         branch_pats+=" '[r]efs/heads/$branch_pat'"
  87 done
  88
  89 get_branches_rune='
  90         git for-each-ref --format="%(refname)=%(objectname)" '"$branch_pats"'
  91 '
  92
  93 src_branches=( $(
  94         on_src '
  95                 printf H
  96                 git symbolic-ref -q HEAD || test $? = 1
  97                 echo " "
  98                 '"$get_branches_rune"'
  99         '
 100 ))
 101
 102 src_head="${src_branches[0]}"
 103 unset src_branches[0]
 104 : "${src_branches[@]}"
 105
 106 case "$src_head" in
 107 H) ;; # already detached
 108 *)
 109         src_head="${src_head#H}"
 110         for check in "${src_branches[@]}"; do
 111                 case "$check" in
 112                 "$src_head"=*)
 113                         fail "would delete checked-out branch $src_head"
 114                         ;;
 115                 esac
 116         done
 117         ;;
 118 esac
 119
 120
 121 if [ "${#src_branches[@]}" = 0 ]; then
 122         echo >&2 "git-branchmove: nothing to do"
 123         exit 1
 124 fi
 125
 126 dst_branches=( $(on_dst "$get_branches_rune") )
 127 : "${dst_branches[@]}"
 128
 129
 130 #----- check for nonequal overlaps -----
 131
 132 ok=true
 133 for dst_check in "${dst_branches[@]}"; do
 134         dst_ref="${dst_check%=*}"
 135         for src_check in "${src_branches[@]}"; do
 136                 case "$src_check" in
 137                 "$dst_check")   ;;
 138                 "$dst_ref"=*)
 139                         ok=false
 140                         echo >&2 "src: $src_check   dst: $dst_check"
 141                         ;;
 142                 esac
 143         done
 144 done
 145
 146 $ok || fail "would overwrite some destination branch(es)"
 147
 148
 149 #----- do the transfer -----
 150
 151 refspecs=()
 152 for src_xfer in "${src_branches[@]}"; do
 153         src_ref="${src_xfer%=*}"
 154         refspecs+=("$src_ref:$src_ref")
 155 done
 156
 157 case "$op" in
 158 put)    git push "$remote" "${refspecs[@]}"     ;;
 159 get)    git fetch "$remote" "${refspecs[@]}"    ;;
 160 *)      fail "unknown $op ???"                  ;;
 161 esac
 162
 163
 164 #----- delete the refs on the source -----
 165
 166 (
 167         printf "%s\n" "$updatemsg"
 168         for src_rm in "${src_branches[@]}"; do printf "%s\n" "$src_rm"; done
 169 ) | on_src '
 170         read updatemsg
 171         while read src_rm; do
 172                 src_ref="${src_rm%=*}"
 173                 src_obj="${src_rm##*=}"
 174                 git update-ref -m "$updatemsg" -d "$src_ref" "$src_obj"
 175                 echo "moved: $src_ref"
 176         done
 177 '
 178
 179 #----- update the remote tracking branches -----
 180
 181 if [ "x$remotename" != x ]; then
 182         for src_rm in "${src_branches[@]}"; do
 183                 src_ref="${src_rm%=*}"
 184                 src_obj="${src_rm##*=}"
 185
 186                 case "$src_ref" in
 187                 refs/heads/*) ;;
 188                 *) continue ;;
 189                 esac
 190
 191                 branch="${src_ref#refs/heads/}"
 192                 track_ref="refs/remotes/$remotename/$branch"
 193                 case $op in
 194                 get)    git update-ref -d "$track_ref"  ;;
 195                 put)    git update-ref "$track_ref" "$src_obj" ;;
 196                 *)      fail "unknown $op ???"
 197                 esac
 198         done
 199 fi
 200
 201 echo "git-repomove: moved ${#src_branches[@]} branches."