1 files changed, 86 insertions, 0 deletions
diff --git a/git-merge-octopus.sh b/git-merge-octopus.sh
new file mode 100755
index 0000000000..aa1cd2f106
--- /dev/null
+++ b/git-merge-octopus.sh
@@ -0,0 +1,86 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+#
+# Resolve two or more trees.
+#
+
+# The first parameters up to -- are merge bases; the rest are heads.
+bases= head= remotes= sep_seen=
+for arg
+do
+	case ",$sep_seen,$head,$arg," in
+	*,--,)
+		sep_seen=yes
+		;;
+	,yes,,*)
+		head=$arg
+		;;
+	,yes,*)
+		remotes="$remotes$arg "
+		;;
+	*)
+		bases="$bases$arg "
+		;;
+	esac
+done
+
+# Reject if this is not an Octopus -- resolve should be used instead.
+case "$remotes" in
+?*' '?*)
+	;;
+*)
+	exit 2 ;;
+esac
+
+# MRC is the current "merge reference commit"
+# MRT is the current "merge result tree"
+
+MRC=$head MSG= PARENT="-p $head"
+MRT=$(git-write-tree)
+CNT=1 ;# counting our head
+NON_FF_MERGE=0
+for SHA1 in $remotes
+do
+	common=$(git-merge-base $MRC $SHA1) ||
+		die "Unable to find common commit with $SHA1"
+
+	if test "$common" = $SHA1
+	then
+		echo "Already up-to-date with $SHA1"
+		continue
+	fi
+
+	CNT=`expr $CNT + 1`
+	PARENT="$PARENT -p $SHA1"
+
+	if test "$common,$NON_FF_MERGE" = "$MRC,0"
+	then
+		# The first head being merged was a fast-forward.
+		# Advance MRC to the head being merged, and use that
+		# tree as the intermediate result of the merge.
+		# We still need to count this as part of the parent set.
+
+		echo "Fast forwarding to: $SHA1"
+		git-read-tree -u -m $head $SHA1 || exit
+		MRC=$SHA1 MRT=$(git-write-tree)
+		continue
+	fi
+
+	NON_FF_MERGE=1
+
+	echo "Trying simple merge with $SHA1"
+	git-read-tree -u -m $common $MRT $SHA1 || exit 2
+	next=$(git-write-tree 2>/dev/null)
+	if test $? -ne 0
+	then
+		echo "Simple merge did not work, trying automatic merge."
+		git-merge-index -o git-merge-one-file -a ||
+		exit 2 ; # Automatic merge failed; should not be doing Octopus
+		next=$(git-write-tree 2>/dev/null)
+	fi
+	MRC=$common
+	MRT=$next
+done
+
+exit 0