Fixed merge algorithm regarding adjacent modifications

JGit merge algorithm behaved differently from C Git when
we had adjacent modifications. If line 9 was modified by
OURS and line 10 by theirs then C Git will return a
conflict while JGit was seeing this as independent
modifications. This change is not only there to achieve
compatibility, but there where also some really wrong
merge results produced by JGit in the area of adjacent
modifications.

Change-Id: I8d77cb59e82638214e45b3cf9ce3a1f1e9b35c70
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergeAlgorithmTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergeAlgorithmTest.java
index c929629502..9b4b7146f6 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergeAlgorithmTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/merge/MergeAlgorithmTest.java
@@ -107,7 +107,7 @@ public class MergeAlgorithmTest extends TestCase {
 	 * @throws IOException
 	 */
 	public void testTwoComplicatedModifications() throws IOException {
-		assertEquals(t("a<ZZZZfZh=bYdYYYY>ZY"),
+		assertEquals(t("a<ZZZZfZhZj=bYdYYYYiY>"),
 				merge("abcdefghij", "aZZZZfZhZj", "abYdYYYYiY"));
 	}
 
@@ -153,6 +153,18 @@ public class MergeAlgorithmTest extends TestCase {
 				merge("abcdefghij", "abdefghij", "abZdefghij"));
 	}
 
+	public void testInsertVsModify() throws IOException {
+		assertEquals(t("a<bZ=XY>"), merge("ab", "abZ", "aXY"));
+	}
+
+	public void testAdjacentModifications() throws IOException {
+		assertEquals(t("a<Zc=bY>d"), merge("abcd", "aZcd", "abYd"));
+	}
+
+	public void testSeperateModifications() throws IOException {
+		assertEquals(t("aZcYe"), merge("abcde", "aZcde", "abcYe"));
+	}
+
 	private String merge(String commonBase, String ours, String theirs) throws IOException {
 		MergeResult r = MergeAlgorithm.merge(RawTextComparator.DEFAULT,
 				T(commonBase), T(ours), T(theirs));