diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index a026fd46b4..4bfffa9c31 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -488,6 +488,51 @@ test_expect_success PERL 'required process filter should filter data for various
 			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
 			STOP
 		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		git checkout -b merge empty-branch &&
+		git branch -f master $MASTER2 &&
+		filter_git merge master &&
+		META="treeish=$MASTER2" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		filter_git archive master >/dev/null &&
+		META="ref=refs/heads/master treeish=$MASTER2" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log debug.log &&
+
+		TREE="$(git rev-parse $MASTER2^{tree})" &&
+		filter_git archive $TREE >/dev/null &&
+		META="treeish=$TREE" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $META blob=$M2 $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r $META blob=$EMPTY 0 [OK] -- OUT: 0  [OK]
+			IN: smudge test5.r $META blob=$M $S [OK] -- OUT: $S . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x=.r $META blob=$M3 $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
 		test_cmp_exclude_clean expected.log debug.log
 	)
 '