Fix git-log-script when HEAD is invalid.
[git] / git-resolve-script
1 #!/bin/sh
2 #
3 # Copyright (c) 2005 Linus Torvalds
4 #
5 # Resolve two trees.
6 #
7 . git-sh-setup-script || die "Not a git archive"
8
9 usage () {
10         die "git-resolve-script <head> <remote> <merge-message>"
11 }
12
13 dropheads() {
14         rm -f -- "$GIT_DIR/MERGE_HEAD" \
15                 "$GIT_DIR/LAST_MERGE" || exit 1
16 }
17
18 head=$(git-rev-parse --verify "$1"^0) &&
19 merge=$(git-rev-parse --verify "$2"^0) &&
20 merge_msg="$3" || usage
21
22 #
23 # The remote name is just used for the message,
24 # but we do want it.
25 #
26 if [ -z "$head" -o -z "$merge" -o -z "$merge_msg" ]; then
27         usage
28 fi
29
30 dropheads
31 echo $head > "$GIT_DIR"/ORIG_HEAD
32 echo $merge > "$GIT_DIR"/LAST_MERGE
33
34 common=$(git-merge-base $head $merge)
35 if [ -z "$common" ]; then
36         die "Unable to find common commit between" $merge $head
37 fi
38
39 if [ "$common" == "$merge" ]; then
40         echo "Already up-to-date. Yeeah!"
41         dropheads
42         exit 0
43 fi
44 if [ "$common" == "$head" ]; then
45         echo "Updating from $head to $merge."
46         git-read-tree -u -m $head $merge || exit 1
47         echo $merge > "$GIT_DIR"/HEAD
48         git-diff-tree -p $head $merge | git-apply --stat
49         dropheads
50         exit 0
51 fi
52
53 # Find an optimum merge base if there are more than one candidates.
54 LF='
55 '
56 common=$(git-merge-base -a $head $merge)
57 case "$common" in
58 ?*"$LF"?*)
59         echo "Trying to find the optimum merge base."
60         G=.tmp-index$$
61         best=
62         best_cnt=-1
63         for c in $common
64         do
65                 rm -f $G
66                 GIT_INDEX_FILE=$G git-read-tree -m $c $head $merge \
67                         2>/dev/null || continue
68                 # Count the paths that are unmerged.
69                 cnt=`GIT_INDEX_FILE=$G git-ls-files --unmerged | wc -l`
70                 if test $best_cnt -le 0 -o $cnt -le $best_cnt
71                 then
72                         best=$c
73                         best_cnt=$cnt
74                         if test "$best_cnt" -eq 0
75                         then
76                                 # Cannot do any better than all trivial merge.
77                                 break
78                         fi
79                 fi
80         done
81         rm -f $G
82         common="$best"
83 esac
84
85 echo "Trying to merge $merge into $head using $common."
86 git-update-cache --refresh 2>/dev/null
87 git-read-tree -u -m $common $head $merge || exit 1
88 result_tree=$(git-write-tree  2> /dev/null)
89 if [ $? -ne 0 ]; then
90         echo "Simple merge failed, trying Automatic merge"
91         git-merge-cache -o git-merge-one-file-script -a
92         if [ $? -ne 0 ]; then
93                 echo $merge > "$GIT_DIR"/MERGE_HEAD
94                 die "Automatic merge failed, fix up by hand"
95         fi
96         result_tree=$(git-write-tree) || exit 1
97 fi
98 result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree -p $head -p $merge)
99 echo "Committed merge $result_commit"
100 echo $result_commit > "$GIT_DIR"/HEAD
101 git-diff-tree -p $head $result_commit | git-apply --stat
102 dropheads