git-revert-script

   1 #!/bin/sh
   2 . git-sh-setup-script || die "Not a git archive"
   3
   4 # We want a clean tree and clean index to be able to revert.
   5 status=$(git status)
   6 case "$status" in
   7 'nothing to commit') ;;
   8 *)
   9         echo "$status"
  10         die "Your working tree is dirty; cannot revert a previous patch." ;;
  11 esac
  12
  13 rev=$(git-rev-parse --no-flags --verify --revs-only "$@") &&
  14 commit=$(git-rev-parse --verify "$rev^0") || exit
  15 if git-diff-tree -R -M -p $commit | git-apply --index &&
  16    msg=$(git-rev-list --pretty=oneline --max-count=1 $commit)
  17 then
  18         {
  19                 echo "$msg" | sed -e '
  20                         s/^[^ ]* /Revert "/
  21                         s/$/"/'
  22                 echo
  23                 echo "This reverts $commit commit."
  24                 test "$rev" = "$commit" ||
  25                 echo "(original 'git revert' arguments: $@)"
  26         } | git commit -F -
  27 else
  28         # Now why did it fail?
  29         parents=`git-cat-file commit "$commit" 2>/dev/null |
  30                 sed -ne '/^$/q;/^parent /p' |
  31                 wc -l`
  32         case $parents in
  33         0) die "Cannot revert the root commit nor non commit-ish." ;;
  34         1) die "The patch does not apply." ;;
  35         *) die "Cannot revert a merge commit." ;;
  36         esac
  37 fi