1 files changed, 70 insertions, 1 deletions
diff --git a/t/t6026-merge-attr.sh b/t/t6026-merge-attr.sh
index 5daa2236d..1732b60ed 100755
--- a/t/t6026-merge-attr.sh
+++ b/t/t6026-merge-attr.sh
@@ -30,8 +30,9 @@ test_expect_success setup '
 		echo Side >>$f && git add $f || break
 	done &&
 	test_tick &&
-	git commit -m Side
+	git commit -m Side &&
 
+	git tag anchor
 '
 
 test_expect_success merge '
@@ -69,4 +70,72 @@ test_expect_success 'check merge result in working tree' '
 
 '
 
+cat >./custom-merge <<\EOF
+#!/bin/sh
+
+orig="$1" ours="$2" theirs="$3" exit="$4"
+(
+	echo "orig is $orig"
+	echo "ours is $ours"
+	echo "theirs is $theirs"
+	echo "=== orig ==="
+	cat "$orig"
+	echo "=== ours ==="
+	cat "$ours"
+	echo "=== theirs ==="
+	cat "$theirs"
+) >"$ours+"
+cat "$ours+" >"$ours"
+rm -f "$ours+"
+exit "$exit"
+EOF
+chmod +x ./custom-merge
+
+test_expect_success 'custom merge backend' '
+
+	echo "* merge=union" >.gitattributes &&
+	echo "text merge=custom" >>.gitattributes &&
+
+	git reset --hard anchor &&
+	git config --replace-all \
+	merge.driver "custom ./custom-merge %O %A %B 0" &&
+
+	git merge master &&
+
+	cmp binary union &&
+	sed -e 1,3d text >check-1 &&
+	o=$(git-unpack-file master^:text) &&
+	a=$(git-unpack-file side^:text) &&
+	b=$(git-unpack-file master:text) &&
+	sh -c "./custom-merge $o $a $b 0" &&
+	sed -e 1,3d $a >check-2 &&
+	cmp check-1 check-2 &&
+	rm -f $o $a $b
+'
+
+test_expect_success 'custom merge backend' '
+
+	git reset --hard anchor &&
+	git config --replace-all \
+	merge.driver "custom ./custom-merge %O %A %B 1" &&
+
+	if git merge master
+	then
+		echo "Eh? should have conflicted"
+		false
+	else
+		echo "Ok, conflicted"
+	fi &&
+
+	cmp binary union &&
+	sed -e 1,3d text >check-1 &&
+	o=$(git-unpack-file master^:text) &&
+	a=$(git-unpack-file anchor:text) &&
+	b=$(git-unpack-file master:text) &&
+	sh -c "./custom-merge $o $a $b 0" &&
+	sed -e 1,3d $a >check-2 &&
+	cmp check-1 check-2 &&
+	rm -f $o $a $b
+'
+
 test_done