Added TestCase for 7d5e1f Fixed RevWalk.isMergedInto()

Change-Id: Id9a641dd67c4182bb3a0dc83a6864fee43e7653f
Signed-off-by: Gustaf Lundh <gustaf.lundh@sonymobile.com>
Signed-off-by: Sven Selberg <sven.selberg@sonymobile.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevWalkMergedIntoTest.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2014, Sven Selberg <sven.selberg@sonymobile.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.revwalk;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class RevWalkMergedIntoTest extends RevWalkTestCase {
+
+	@Test
+	public void testOldCommitWalk() throws Exception {
+		/*
+		 * Sometimes a merge is performed on a machine with faulty time.
+		 * This makes the traversal of the graph, when trying to find out if B
+		 * is merged into T, complex since the algorithm uses the time stamps
+		 * of commits to find the best route.
+		 * When for example O(ld) has a very old time stamp compared to one of the
+		 * commits (N(ew)) on the upper route between T and F(alse base), the route
+		 * to False is deemed the better option even though the alternate route leeds
+		 * to B(ase) which was the commit we were after.
+		 *
+		 *             o---o---o---o---N
+		 *            /                 \
+		 *           /   o---o---o---O---T
+		 *          /   /
+		 *      ---F---B
+		 *
+		 * This test is asserting that isMergedInto(B, T) returns true even
+		 * under those circumstances.
+		 */
+		final int threeDaysInSecs = 3 * 24 * 60 * 60;
+		final RevCommit f = commit();
+		final RevCommit b = commit(f);
+		final RevCommit o = commit(-threeDaysInSecs, commit(commit(commit(b))));
+		final RevCommit n = commit(commit(commit(commit(commit(f)))));
+		final RevCommit t = commit(n, o);
+		assertTrue(rw.isMergedInto(b, t));
+	}
+}