Handle missing "ours" stage in WorkingTreeIterator.hasCrLfInIndex()

In a delete-modify conflict with the deletion as "ours" there may be
no stage 2 in the index. Add appropriate null checks. Add a new test
for this case, and verify that the file gets added with a single LF
after conflict resolution with core.autocrlf=true. This matches the
behavior of canonical git for this case.

Bug: 547724
Change-Id: I1bafdb83d9b78bf85294c78325e818e72fae53bc
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CommitCommandTest.java

@@ -661,6 +661,54 @@ public class CommitCommandTest extends RepositoryTestCase {
 		}
 	}
 
+	@Test
+	public void testDeletionConflictWithAutoCrlf() throws Exception {
+		try (Git git = new Git(db)) {
+			// Commit a file with CR/LF into the index
+			FileBasedConfig config = db.getConfig();
+			config.setString("core", null, "autocrlf", "false");
+			config.save();
+			File file = writeTrashFile("file.txt", "foo\r\n");
+			git.add().addFilepattern("file.txt").call();
+			git.commit().setMessage("Initial").call();
+			// Switch to side branch
+			git.checkout().setCreateBranch(true).setName("side").call();
+			assertTrue(file.delete());
+			git.rm().addFilepattern("file.txt").call();
+			git.commit().setMessage("Side").call();
+			// Switch on autocrlf=true
+			config.setString("core", null, "autocrlf", "true");
+			config.save();
+			// Switch back to master and commit a conflict
+			git.checkout().setName("master").call();
+			writeTrashFile("file.txt", "foob\r\n");
+			git.add().addFilepattern("file.txt").call();
+			assertEquals("[file.txt, mode:100644, content:foob\r\n]",
+					indexState(CONTENT));
+			writeTrashFile("g", "file2.txt", "anything");
+			git.add().addFilepattern("g/file2.txt");
+			RevCommit master = git.commit().setMessage("Second").call();
+			// Switch to side branch again so that the deletion is "ours"
+			git.checkout().setName("side").call();
+			// Cherry pick master: produces a delete-modify conflict.
+			CherryPickResult pick = git.cherryPick().include(master).call();
+			assertEquals("Expected a cherry-pick conflict",
+					CherryPickStatus.CONFLICTING, pick.getStatus());
+			// XXX: g/file2.txt should actually be staged already, but isn't.
+			git.add().addFilepattern("g/file2.txt").call();
+			// Resolve the conflict by taking the master version
+			writeTrashFile("file.txt", "foob\r\n");
+			git.add().addFilepattern("file.txt").call();
+			git.commit().setMessage("Cherry").call();
+			// We expect this to be committed with a single LF since there is no
+			// "ours" stage.
+			assertEquals(
+					"[file.txt, mode:100644, content:foob\n]"
+							+ "[g/file2.txt, mode:100644, content:anything]",
+					indexState(CONTENT));
+		}
+	}
+
 	private void testConflictWithAutoCrlf(String baseLf, String lf)
 			throws Exception {
 		try (Git git = new Git(db)) {

org.eclipse.jgit/src/org/eclipse/jgit/treewalk/WorkingTreeIterator.java

@@ -1516,6 +1516,7 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 			ObjectId blobId = entry.getObjectId();
 			if (entry.getStage() > 0
 					&& entry.getStage() != DirCacheEntry.STAGE_2) {
+				blobId = null;
 				// Merge conflict: check ours (stage 2)
 				byte[] name = entry.getRawPath();
 				int i = 0;
@@ -1523,7 +1524,8 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 					dirCache.next(1);
 					i++;
 					entry = dirCache.getDirCacheEntry();
-					if (!Arrays.equals(name, entry.getRawPath())) {
+					if (entry == null
+							|| !Arrays.equals(name, entry.getRawPath())) {
 						break;
 					}
 					if (entry.getStage() == DirCacheEntry.STAGE_2) {
@@ -1533,8 +1535,10 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 				}
 				dirCache.back(i);
 			}
+			if (blobId != null) {
 				try (ObjectReader reader = repository.newObjectReader()) {
-				ObjectLoader loader = reader.open(blobId, Constants.OBJ_BLOB);
+					ObjectLoader loader = reader.open(blobId,
+							Constants.OBJ_BLOB);
 					try {
 						return RawText.isCrLfText(loader.getCachedBytes());
 					} catch (LargeObjectException e) {
@@ -1546,6 +1550,7 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 					// Ignore and return false below
 				}
 			}
+		}
 		return false;
 	}