trivial: O_EXCL makes O_TRUNC redundant
[alt-git.git] / git-revert.sh
blob63d201be1bf810499cfeb7aecbc23ec15e171bb7
1 #!/bin/sh
3 # Copyright (c) 2005 Linus Torvalds
4 # Copyright (c) 2005 Junio C Hamano
7 case "$0" in
8 *-revert* )
9 test -t 0 && edit=-e
10 me=revert
11 USAGE='[--edit | --no-edit] [-n] <commit-ish>' ;;
12 *-cherry-pick* )
13 edit=
14 me=cherry-pick
15 USAGE='[--edit] [-n] [-r] <commit-ish>' ;;
16 * )
17 die "What are you talking about?" ;;
18 esac
19 . git-sh-setup
21 no_commit= replay=
22 while case "$#" in 0) break ;; esac
24 case "$1" in
25 -n|--n|--no|--no-|--no-c|--no-co|--no-com|--no-comm|\
26 --no-commi|--no-commit)
27 no_commit=t
29 -e|--e|--ed|--edi|--edit)
30 edit=-e
32 --n|--no|--no-|--no-e|--no-ed|--no-edi|--no-edit)
33 edit=
35 -r|--r|--re|--rep|--repl|--repla|--replay)
36 replay=t
38 -*)
39 usage
42 break
44 esac
45 shift
46 done
48 test "$me,$replay" = "revert,t" && usage
50 case "$no_commit" in
52 # We do not intend to commit immediately. We just want to
53 # merge the differences in.
54 head=$(git-write-tree) ||
55 die "Your index file is unmerged."
58 head=$(git-rev-parse --verify HEAD) ||
59 die "You do not have a valid HEAD"
60 files=$(git-diff-index --cached --name-only $head) || exit
61 if [ "$files" ]; then
62 die "Dirty index: cannot $me (dirty: $files)"
65 esac
67 rev=$(git-rev-parse --verify "$@") &&
68 commit=$(git-rev-parse --verify "$rev^0") ||
69 die "Not a single commit $@"
70 prev=$(git-rev-parse --verify "$commit^1" 2>/dev/null) ||
71 die "Cannot run $me a root commit"
72 git-rev-parse --verify "$commit^2" >/dev/null 2>&1 &&
73 die "Cannot run $me a multi-parent commit."
75 # "commit" is an existing commit. We would want to apply
76 # the difference it introduces since its first parent "prev"
77 # on top of the current HEAD if we are cherry-pick. Or the
78 # reverse of it if we are revert.
80 case "$me" in
81 revert)
82 git-rev-list --pretty=oneline --max-count=1 $commit |
83 sed -e '
84 s/^[^ ]* /Revert "/
85 s/$/"/'
86 echo
87 echo "This reverts $commit commit."
88 test "$rev" = "$commit" ||
89 echo "(original 'git revert' arguments: $@)"
90 base=$commit next=$prev
93 cherry-pick)
94 pick_author_script='
95 /^author /{
97 s/^author \([^<]*\) <[^>]*> .*$/\1/
98 s/'\''/'\''\'\'\''/g
99 s/.*/GIT_AUTHOR_NAME='\''&'\''/p
102 s/^author [^<]* <\([^>]*\)> .*$/\1/
103 s/'\''/'\''\'\'\''/g
104 s/.*/GIT_AUTHOR_EMAIL='\''&'\''/p
107 s/^author [^<]* <[^>]*> \(.*\)$/\1/
108 s/'\''/'\''\'\'\''/g
109 s/.*/GIT_AUTHOR_DATE='\''&'\''/p
113 set_author_env=`git-cat-file commit "$commit" |
114 LANG=C LC_ALL=C sed -ne "$pick_author_script"`
115 eval "$set_author_env"
116 export GIT_AUTHOR_NAME
117 export GIT_AUTHOR_EMAIL
118 export GIT_AUTHOR_DATE
120 git-cat-file commit $commit | sed -e '1,/^$/d'
121 case "$replay" in
123 echo "(cherry picked from $commit commit)"
124 test "$rev" = "$commit" ||
125 echo "(original 'git cherry-pick' arguments: $@)"
127 esac
128 base=$prev next=$commit
131 esac >.msg
133 # This three way merge is an interesting one. We are at
134 # $head, and would want to apply the change between $commit
135 # and $prev on top of us (when reverting), or the change between
136 # $prev and $commit on top of us (when cherry-picking or replaying).
138 echo >&2 "First trying simple merge strategy to $me."
139 git-read-tree -m -u $base $head $next &&
140 result=$(git-write-tree 2>/dev/null) || {
141 echo >&2 "Simple $me fails; trying Automatic $me."
142 git-merge-index -o git-merge-one-file -a || {
143 echo >&2 "Automatic $me failed. After fixing it up,"
144 echo >&2 "you can use \"git commit -F .msg\""
145 case "$me" in
146 cherry-pick)
147 echo >&2 "You may choose to use the following when making"
148 echo >&2 "the commit:"
149 echo >&2 "$set_author_env"
150 esac
151 exit 1
153 result=$(git-write-tree) || exit
155 echo >&2 "Finished one $me."
157 # If we are cherry-pick, and if the merge did not result in
158 # hand-editing, we will hit this commit and inherit the original
159 # author date and name.
160 # If we are revert, or if our cherry-pick results in a hand merge,
161 # we had better say that the current user is responsible for that.
163 case "$no_commit" in
165 git-commit -n -F .msg $edit
166 rm -f .msg
168 esac