1#!/bin/sh
2#
3# Copyright (c) 2005 Junio C Hamano
4#
5# Resolve two or more trees.
6#
7
8. git-sh-setup
9
10LF='
11'
12
13# The first parameters up to -- are merge bases; the rest are heads.
14bases= head= remotes= sep_seen=
15for arg
16do
17	case ",$sep_seen,$head,$arg," in
18	*,--,)
19		sep_seen=yes
20		;;
21	,yes,,*)
22		head=$arg
23		;;
24	,yes,*)
25		remotes="$remotes$arg "
26		;;
27	*)
28		bases="$bases$arg "
29		;;
30	esac
31done
32
33# Reject if this is not an octopus -- resolve should be used instead.
34case "$remotes" in
35?*' '?*)
36	;;
37*)
38	exit 2 ;;
39esac
40
41# MRC is the current "merge reference commit"
42# MRT is the current "merge result tree"
43
44if ! git diff-index --quiet --cached HEAD --
45then
46    gettextln "Error: Your local changes to the following files would be overwritten by merge"
47    git diff-index --cached --name-only HEAD -- | sed -e 's/^/    /'
48    exit 2
49fi
50MRC=$(git rev-parse --verify -q $head)
51MRT=$(git write-tree)
52NON_FF_MERGE=0
53OCTOPUS_FAILURE=0
54for SHA1 in $remotes
55do
56	case "$OCTOPUS_FAILURE" in
57	1)
58		# We allow only last one to have a hand-resolvable
59		# conflicts.  Last round failed and we still had
60		# a head to merge.
61		gettextln "Automated merge did not work."
62		gettextln "Should not be doing an octopus."
63		exit 2
64	esac
65
66	eval pretty_name=\${GITHEAD_$SHA1:-$SHA1}
67	if test "$SHA1" = "$pretty_name"
68	then
69		SHA1_UP="$(echo "$SHA1" | tr a-z A-Z)"
70		eval pretty_name=\${GITHEAD_$SHA1_UP:-$pretty_name}
71	fi
72	common=$(git merge-base --all $SHA1 $MRC) ||
73		die "$(eval_gettext "Unable to find common commit with \$pretty_name")"
74
75	case "$LF$common$LF" in
76	*"$LF$SHA1$LF"*)
77		eval_gettextln "Already up to date with \$pretty_name"
78		continue
79		;;
80	esac
81
82	if test "$common,$NON_FF_MERGE" = "$MRC,0"
83	then
84		# The first head being merged was a fast-forward.
85		# Advance MRC to the head being merged, and use that
86		# tree as the intermediate result of the merge.
87		# We still need to count this as part of the parent set.
88
89		eval_gettextln "Fast-forwarding to: \$pretty_name"
90		git read-tree -u -m $head $SHA1 || exit
91		MRC=$SHA1 MRT=$(git write-tree)
92		continue
93	fi
94
95	NON_FF_MERGE=1
96
97	eval_gettextln "Trying simple merge with \$pretty_name"
98	git read-tree -u -m --aggressive  $common $MRT $SHA1 || exit 2
99	next=$(git write-tree 2>/dev/null)
100	if test $? -ne 0
101	then
102		gettextln "Simple merge did not work, trying automatic merge."
103		git merge-index -o git-merge-one-file -a ||
104		OCTOPUS_FAILURE=1
105		next=$(git write-tree 2>/dev/null)
106	fi
107
108	MRC="$MRC $SHA1"
109	MRT=$next
110done
111
112exit "$OCTOPUS_FAILURE"
113