contrib/git-resurrect.sh

   1 #!/bin/sh
   2
   3 USAGE="[-a] [-r] [-m] [-t] [-n] [-b <newname>] <name>"
   4 LONG_USAGE="git-resurrect attempts to find traces of a branch tip
   5 called <name>, and tries to resurrect it.  Currently, the reflog is
   6 searched for checkout messages, and with -r also merge messages.  With
   7 -m and -t, the history of all refs is scanned for Merge <name> into
   8 other/Merge <other> into <name> (respectively) commit subjects, which
   9 is rather slow but allows you to resurrect other people's topic
  10 branches."
  11
  12 OPTIONS_KEEPDASHDASH=
  13 OPTIONS_STUCKLONG=
  14 OPTIONS_SPEC="\
  15 git resurrect $USAGE
  16 --
  17 b,branch=            save branch as <newname> instead of <name>
  18 a,all                same as -l -r -m -t
  19 k,keep-going         full rev-list scan (instead of first match)
  20 l,reflog             scan reflog for checkouts (enabled by default)
  21 r,reflog-merges      scan for merges recorded in reflog
  22 m,merges             scan for merges into other branches (slow)
  23 t,merge-targets      scan for merges of other branches into <name>
  24 n,dry-run            don't recreate the branch"
  25
  26 . git-sh-setup
  27
  28 search_reflog () {
  29         sed -ne 's~^\([^ ]*\) .*\tcheckout: moving from '"$1"' .*~\1~p' \
  30                 < "$GIT_DIR"/logs/HEAD
  31 }
  32
  33 search_reflog_merges () {
  34         git rev-parse $(
  35                 sed -ne 's~^[^ ]* \([^ ]*\) .*\tmerge '"$1"':.*~\1^2~p' \
  36                         < "$GIT_DIR"/logs/HEAD
  37         )
  38 }
  39
  40 _x40="[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]"
  41 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
  42
  43 search_merges () {
  44         git rev-list --all --grep="Merge branch '$1'" \
  45                 --pretty=tformat:"%P %s" |
  46         sed -ne "/^$_x40 \($_x40\) Merge .*/ {s//\1/p;$early_exit}"
  47 }
  48
  49 search_merge_targets () {
  50         git rev-list --all --grep="Merge branch '[^']*' into $branch\$" \
  51                 --pretty=tformat:"%H %s" --all |
  52         sed -ne "/^\($_x40\) Merge .*/ {s//\1/p;$early_exit} "
  53 }
  54
  55 dry_run=
  56 early_exit=q
  57 scan_reflog=t
  58 scan_reflog_merges=
  59 scan_merges=
  60 scan_merge_targets=
  61 new_name=
  62
  63 while test "$#" != 0; do
  64         case "$1" in
  65             -b|--branch)
  66                 shift
  67                 new_name="$1"
  68                 ;;
  69             -n|--dry-run)
  70                 dry_run=t
  71                 ;;
  72             --no-dry-run)
  73                 dry_run=
  74                 ;;
  75             -k|--keep-going)
  76                 early_exit=
  77                 ;;
  78             --no-keep-going)
  79                 early_exit=q
  80                 ;;
  81             -m|--merges)
  82                 scan_merges=t
  83                 ;;
  84             --no-merges)
  85                 scan_merges=
  86                 ;;
  87             -l|--reflog)
  88                 scan_reflog=t
  89                 ;;
  90             --no-reflog)
  91                 scan_reflog=
  92                 ;;
  93             -r|--reflog_merges)
  94                 scan_reflog_merges=t
  95                 ;;
  96             --no-reflog_merges)
  97                 scan_reflog_merges=
  98                 ;;
  99             -t|--merge-targets)
 100                 scan_merge_targets=t
 101                 ;;
 102             --no-merge-targets)
 103                 scan_merge_targets=
 104                 ;;
 105             -a|--all)
 106                 scan_reflog=t
 107                 scan_reflog_merges=t
 108                 scan_merges=t
 109                 scan_merge_targets=t
 110                 ;;
 111             --)
 112                 shift
 113                 break
 114                 ;;
 115             *)
 116                 usage
 117                 ;;
 118         esac
 119         shift
 120 done
 121
 122 test "$#" = 1 || usage
 123
 124 all_strategies="$scan_reflog$scan_reflog_merges$scan_merges$scan_merge_targets"
 125 if test -z "$all_strategies"; then
 126         die "must enable at least one of -lrmt"
 127 fi
 128
 129 branch="$1"
 130 test -z "$new_name" && new_name="$branch"
 131
 132 if test ! -z "$scan_reflog"; then
 133         if test -r "$GIT_DIR"/logs/HEAD; then
 134                 candidates="$(search_reflog $branch)"
 135         else
 136                 die 'reflog scanning requested, but' \
 137                         '$GIT_DIR/logs/HEAD not readable'
 138         fi
 139 fi
 140 if test ! -z "$scan_reflog_merges"; then
 141         if test -r "$GIT_DIR"/logs/HEAD; then
 142                 candidates="$candidates $(search_reflog_merges $branch)"
 143         else
 144                 die 'reflog scanning requested, but' \
 145                         '$GIT_DIR/logs/HEAD not readable'
 146         fi
 147 fi
 148 if test ! -z "$scan_merges"; then
 149         candidates="$candidates $(search_merges $branch)"
 150 fi
 151 if test ! -z "$scan_merge_targets"; then
 152         candidates="$candidates $(search_merge_targets $branch)"
 153 fi
 154
 155 candidates="$(git rev-parse $candidates | sort -u)"
 156
 157 if test -z "$candidates"; then
 158         hint=
 159         test "z$all_strategies" != "ztttt" \
 160                 && hint=" (maybe try again with -a)"
 161         die "no candidates for $branch found$hint"
 162 fi
 163
 164 echo "** Candidates for $branch **"
 165 for cmt in $candidates; do
 166         git --no-pager log --pretty=tformat:"%ct:%h [%cr] %s" --abbrev-commit -1 $cmt
 167 done \
 168 | sort -n | cut -d: -f2-
 169
 170 newest="$(git rev-list -1 $candidates)"
 171 if test ! -z "$dry_run"; then
 172         printf "** Most recent: "
 173         git --no-pager log -1 --pretty=tformat:"%h %s" $newest
 174 elif ! git rev-parse --verify --quiet $new_name >/dev/null; then
 175         printf "** Restoring $new_name to "
 176         git --no-pager log -1 --pretty=tformat:"%h %s" $newest
 177         git branch $new_name $newest
 178 else
 179         printf "Most recent: "
 180         git --no-pager log -1 --pretty=tformat:"%h %s" $newest
 181         echo "** $new_name already exists, doing nothing"
 182 fi