t0021: test filter metadata for additional cases

Check that we get the expected data when performing a merges or
generating archives.  Note that we don't expect a ref for merges,
because we won't be checking out any particular ref, but instead a tree
of the merged data.  For archives, however, we expect a ref as normal if
we have one.

Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

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
 	)
 '