Andrew's git / gitweb.git / git-filter-branch.sh
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git-filter-branch.shon commit filter-branch: fail gracefully when a filter fails (8c1ce0f)
   1#!/bin/sh
   2#
   3# Rewrite revision history
   4# Copyright (c) Petr Baudis, 2006
   5# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
   6#
   7# Lets you rewrite the revision history of the current branch, creating
   8# a new branch. You can specify a number of filters to modify the commits,
   9# files and trees.
  10
  11set -e
  12
  13USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
  14. git-sh-setup
  15
  16warn () {
  17        echo "$*" >&2
  18}
  19
  20map()
  21{
  22        # if it was not rewritten, take the original
  23        if test -r "$workdir/../map/$1"
  24        then
  25                cat "$workdir/../map/$1"
  26        else
  27                echo "$1"
  28        fi
  29}
  30
  31# override die(): this version puts in an extra line break, so that
  32# the progress is still visible
  33
  34die()
  35{
  36        echo >&2
  37        echo "$*" >&2
  38        exit 1
  39}
  40
  41# When piped a commit, output a script to set the ident of either
  42# "author" or "committer
  43
  44set_ident () {
  45        lid="$(echo "$1" | tr "A-Z" "a-z")"
  46        uid="$(echo "$1" | tr "a-z" "A-Z")"
  47        pick_id_script='
  48                /^'$lid' /{
  49                        s/'\''/'\''\\'\'\''/g
  50                        h
  51                        s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
  52                        s/'\''/'\''\'\'\''/g
  53                        s/.*/export GIT_'$uid'_NAME='\''&'\''/p
  54
  55                        g
  56                        s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
  57                        s/'\''/'\''\'\'\''/g
  58                        s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
  59
  60                        g
  61                        s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
  62                        s/'\''/'\''\'\'\''/g
  63                        s/.*/export GIT_'$uid'_DATE='\''&'\''/p
  64
  65                        q
  66                }
  67        '
  68
  69        LANG=C LC_ALL=C sed -ne "$pick_id_script"
  70        # Ensure non-empty id name.
  71        echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
  72}
  73
  74tempdir=.git-rewrite
  75filter_env=
  76filter_tree=
  77filter_index=
  78filter_parent=
  79filter_msg=cat
  80filter_commit='git commit-tree "$@"'
  81filter_tag_name=
  82filter_subdir=
  83while case "$#" in 0) usage;; esac
  84do
  85        case "$1" in
  86        --)
  87                shift
  88                break
  89                ;;
  90        -*)
  91                ;;
  92        *)
  93                break;
  94        esac
  95
  96        # all switches take one argument
  97        ARG="$1"
  98        case "$#" in 1) usage ;; esac
  99        shift
 100        OPTARG="$1"
 101        shift
 102
 103        case "$ARG" in
 104        -d)
 105                tempdir="$OPTARG"
 106                ;;
 107        --env-filter)
 108                filter_env="$OPTARG"
 109                ;;
 110        --tree-filter)
 111                filter_tree="$OPTARG"
 112                ;;
 113        --index-filter)
 114                filter_index="$OPTARG"
 115                ;;
 116        --parent-filter)
 117                filter_parent="$OPTARG"
 118                ;;
 119        --msg-filter)
 120                filter_msg="$OPTARG"
 121                ;;
 122        --commit-filter)
 123                filter_commit="$OPTARG"
 124                ;;
 125        --tag-name-filter)
 126                filter_tag_name="$OPTARG"
 127                ;;
 128        --subdirectory-filter)
 129                filter_subdir="$OPTARG"
 130                ;;
 131        *)
 132                usage
 133                ;;
 134        esac
 135done
 136
 137dstbranch="$1"
 138shift
 139test -n "$dstbranch" || die "missing branch name"
 140git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
 141        die "branch $dstbranch already exists"
 142
 143test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
 144mkdir -p "$tempdir/t"
 145cd "$tempdir/t"
 146workdir="$(pwd)"
 147
 148case "$GIT_DIR" in
 149/*)
 150        ;;
 151*)
 152        GIT_DIR="$(pwd)/../../$GIT_DIR"
 153        ;;
 154esac
 155export GIT_DIR GIT_WORK_TREE=.
 156
 157export GIT_INDEX_FILE="$(pwd)/../index"
 158git read-tree # seed the index file
 159
 160ret=0
 161
 162
 163mkdir ../map # map old->new commit ids for rewriting parents
 164
 165case "$filter_subdir" in
 166"")
 167        git rev-list --reverse --topo-order --default HEAD \
 168                --parents "$@"
 169        ;;
 170*)
 171        git rev-list --reverse --topo-order --default HEAD \
 172                --parents --full-history "$@" -- "$filter_subdir"
 173esac > ../revs
 174commits=$(cat ../revs | wc -l | tr -d " ")
 175
 176test $commits -eq 0 && die "Found nothing to rewrite"
 177
 178i=0
 179while read commit parents; do
 180        i=$(($i+1))
 181        printf "\rRewrite $commit ($i/$commits)"
 182
 183        case "$filter_subdir" in
 184        "")
 185                git read-tree -i -m $commit
 186                ;;
 187        *)
 188                git read-tree -i -m $commit:"$filter_subdir"
 189        esac
 190
 191        export GIT_COMMIT=$commit
 192        git cat-file commit "$commit" >../commit
 193
 194        eval "$(set_ident AUTHOR <../commit)" ||
 195                die "setting author failed for commit $commit"
 196        eval "$(set_ident COMMITTER <../commit)" ||
 197                die "setting committer failed for commit $commit"
 198        eval "$filter_env" < /dev/null ||
 199                die "env filter failed: $filter_env"
 200
 201        if [ "$filter_tree" ]; then
 202                git checkout-index -f -u -a
 203                # files that $commit removed are now still in the working tree;
 204                # remove them, else they would be added again
 205                git ls-files -z --others | xargs -0 rm -f
 206                eval "$filter_tree" < /dev/null ||
 207                        die "tree filter failed: $filter_tree"
 208
 209                git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
 210                        xargs -0 git update-index --add --replace --remove
 211                git ls-files -z --others | \
 212                        xargs -0 git update-index --add --replace --remove
 213        fi
 214
 215        eval "$filter_index" < /dev/null ||
 216                die "index filter failed: $filter_index"
 217
 218        parentstr=
 219        for parent in $parents; do
 220                for reparent in $(map "$parent"); do
 221                        parentstr="$parentstr -p $reparent"
 222                done
 223        done
 224        if [ "$filter_parent" ]; then
 225                parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
 226                                die "parent filter failed: $filter_parent"
 227        fi
 228
 229        sed -e '1,/^$/d' <../commit | \
 230                eval "$filter_msg" > ../message ||
 231                        die "msg filter failed: $filter_msg"
 232        sh -c "$filter_commit" "git commit-tree" \
 233                $(git write-tree) $parentstr < ../message > ../map/$commit
 234done <../revs
 235
 236src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
 237target_head=$(head -n 1 ../map/$src_head)
 238case "$target_head" in
 239'')
 240        echo Nothing rewritten
 241        ;;
 242*)
 243        git update-ref refs/heads/"$dstbranch" $target_head
 244        if [ $(cat ../map/$src_head | wc -l) -gt 1 ]; then
 245                echo "WARNING: Your commit filter caused the head commit to expand to several rewritten commits. Only the first such commit was recorded as the current $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
 246                sed 's/^/       /' ../map/$src_head >&2
 247                ret=1
 248        fi
 249        ;;
 250esac
 251
 252if [ "$filter_tag_name" ]; then
 253        git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
 254        while read sha1 type ref; do
 255                ref="${ref#refs/tags/}"
 256                # XXX: Rewrite tagged trees as well?
 257                if [ "$type" != "commit" -a "$type" != "tag" ]; then
 258                        continue;
 259                fi
 260
 261                if [ "$type" = "tag" ]; then
 262                        # Dereference to a commit
 263                        sha1t="$sha1"
 264                        sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
 265                fi
 266
 267                [ -f "../map/$sha1" ] || continue
 268                new_sha1="$(cat "../map/$sha1")"
 269                export GIT_COMMIT="$sha1"
 270                new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
 271                        die "tag name filter failed: $filter_tag_name"
 272
 273                echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
 274
 275                if [ "$type" = "tag" ]; then
 276                        # Warn that we are not rewriting the tag object itself.
 277                        warn "unreferencing tag object $sha1t"
 278                fi
 279
 280                git update-ref "refs/tags/$new_ref" "$new_sha1"
 281        done
 282fi
 283
 284cd ../..
 285rm -rf "$tempdir"
 286printf "\nRewritten history saved to the $dstbranch branch\n"
 287
 288exit $ret