Merge branch 'ep/shell-assign-and-export-vars'
[git] / 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