MergedReftable to skip shadowed refs in same reftable

This would allow compact and GC process to clean up duplicate ref names in the reftables.

Change-Id: I2b9df0bf72dba63cc3525e374982e60559a776c2
Signed-off-by: Minh Thai <mthai@google.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java
index adba048e65..ec60bd9137 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java
@@ -218,6 +218,27 @@ public class MergedReftableTest {
 	}
 
 	@Test
+	public void scanDuplicates() throws IOException {
+		List<Ref> delta1 = Arrays.asList(
+				ref("refs/heads/apple", 1),
+				ref("refs/heads/banana", 2));
+		List<Ref> delta2 = Arrays.asList(
+				ref("refs/heads/apple", 3),
+				ref("refs/heads/apple", 4));
+
+		MergedReftable mr = merge(write(delta1, 1000), write(delta2, 2000));
+		try (RefCursor rc = mr.allRefs()) {
+			assertTrue(rc.next());
+			assertEquals("refs/heads/apple", rc.getRef().getName());
+			assertEquals(id(3), rc.getRef().getObjectId());
+			assertTrue(rc.next());
+			assertEquals("refs/heads/banana", rc.getRef().getName());
+			assertEquals(id(2), rc.getRef().getObjectId());
+			assertFalse(rc.next());
+		}
+	}
+
+	@Test
 	public void scanIncludeDeletes() throws IOException {
 		List<Ref> delta1 = Arrays.asList(ref("refs/heads/next", 4));
 		List<Ref> delta2 = Arrays.asList(delete("refs/heads/next"));