Improve MergeResult

Add paths causing abnormal merge failures (e.g. due to unstaged
changes) to the MergeResult returned by MergeCommand. This helps
callers to better handle (e.g. present) merge results.

Change-Id: Idb8cf04c5cecfb6a12cb880e16febfc3b9358564
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

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

@@ -57,6 +57,7 @@ import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.RepositoryState;
 import org.eclipse.jgit.lib.RepositoryTestCase;
 import org.eclipse.jgit.merge.MergeStrategy;
+import org.eclipse.jgit.merge.ResolveMerger.MergeFailureReason;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.junit.Test;
 
@@ -664,7 +665,8 @@ public class MergeCommandTest extends RepositoryTestCase {
 		MergeResult result = git.merge().include(sideCommit.getId())
 				.setStrategy(MergeStrategy.RESOLVE).call();
 
-		checkMergeFailedResult(result, indexState, fileA);
+		checkMergeFailedResult(result, MergeFailureReason.DIRTY_INDEX,
+				indexState, fileA);
 	}
 
 	@Test
@@ -701,7 +703,8 @@ public class MergeCommandTest extends RepositoryTestCase {
 		MergeResult result = git.merge().include(sideCommit.getId())
 				.setStrategy(MergeStrategy.RESOLVE).call();
 
-		checkMergeFailedResult(result, indexState, fileA);
+		checkMergeFailedResult(result, MergeFailureReason.DIRTY_INDEX,
+				indexState, fileA);
 	}
 
 	@Test
@@ -735,7 +738,8 @@ public class MergeCommandTest extends RepositoryTestCase {
 		MergeResult result = git.merge().include(sideCommit.getId())
 				.setStrategy(MergeStrategy.RESOLVE).call();
 
-		checkMergeFailedResult(result, indexState, fileA);
+		checkMergeFailedResult(result, MergeFailureReason.DIRTY_WORKTREE,
+				indexState, fileA);
 	}
 
 	@Test
@@ -771,7 +775,8 @@ public class MergeCommandTest extends RepositoryTestCase {
 		MergeResult result = git.merge().include(sideCommit.getId())
 				.setStrategy(MergeStrategy.RESOLVE).call();
 
-		checkMergeFailedResult(result, indexState, fileA);
+		checkMergeFailedResult(result, MergeFailureReason.DIRTY_WORKTREE,
+				indexState, fileA);
 	}
 
 	private RevCommit addAllAndCommit(final Git git) throws Exception {
@@ -780,8 +785,10 @@ public class MergeCommandTest extends RepositoryTestCase {
 	}
 
 	private void checkMergeFailedResult(final MergeResult result,
+			final MergeFailureReason reason,
 			final String indexState, final File fileA) throws Exception {
 		assertEquals(MergeStatus.FAILED, result.getMergeStatus());
+		assertEquals(reason, result.getFailingPaths().get("a"));
 		assertEquals("a(modified)", read(fileA));
 		assertFalse(new File(db.getWorkTree(), "b").exists());
 		assertEquals("c", read(new File(db.getWorkTree(), "c")));

org.eclipse.jgit/src/org/eclipse/jgit/api/MergeCommand.java

@@ -229,7 +229,7 @@ public class MergeCommand extends GitCommand<MergeResult> {
 								new ObjectId[] {
 										headCommit.getId(), srcCommit.getId() },
 								MergeStatus.FAILED, mergeStrategy,
-								lowLevelResults, null);
+								lowLevelResults, failingPaths, null);
 					} else
 						return new MergeResult(null,
 								merger.getBaseCommit(0, 1),

org.eclipse.jgit/src/org/eclipse/jgit/api/MergeResult.java

@@ -53,6 +53,7 @@ import org.eclipse.jgit.merge.MergeChunk;
 import org.eclipse.jgit.merge.MergeChunk.ConflictState;
 import org.eclipse.jgit.merge.MergeStrategy;
 import org.eclipse.jgit.merge.ResolveMerger;
+import org.eclipse.jgit.merge.ResolveMerger.MergeFailureReason;
 
 /**
  * Encapsulates the result of a {@link MergeCommand}.
@@ -116,6 +117,8 @@ public class MergeResult {
 
 	private MergeStrategy mergeStrategy;
 
+	private Map<String, MergeFailureReason> failingPaths;
+
 	/**
 	 * @param newHead
 	 *            the object the head points at after the merge
@@ -127,10 +130,11 @@ public class MergeResult {
 	 *            all the commits which have been merged together
 	 * @param mergeStatus
 	 *            the status the merge resulted in
+	 * @param lowLevelResults
+	 *            merge results as returned by
+	 *            {@link ResolveMerger#getMergeResults()}
 	 * @param mergeStrategy
 	 *            the used {@link MergeStrategy}
-	 * @param lowLevelResults
-	 *            merge results as returned by {@link ResolveMerger#getMergeResults()}
 	 */
 	public MergeResult(ObjectId newHead, ObjectId base,
 			ObjectId[] mergedCommits, MergeStatus mergeStatus,
@@ -162,12 +166,44 @@ public class MergeResult {
 			MergeStrategy mergeStrategy,
 			Map<String, org.eclipse.jgit.merge.MergeResult<?>> lowLevelResults,
 			String description) {
+		this(newHead, base, mergedCommits, mergeStatus, mergeStrategy,
+				lowLevelResults, null, null);
+	}
+
+	/**
+	 * @param newHead
+	 *            the object the head points at after the merge
+	 * @param base
+	 *            the common base which was used to produce a content-merge. May
+	 *            be <code>null</code> if the merge-result was produced without
+	 *            computing a common base
+	 * @param mergedCommits
+	 *            all the commits which have been merged together
+	 * @param mergeStatus
+	 *            the status the merge resulted in
+	 * @param mergeStrategy
+	 *            the used {@link MergeStrategy}
+	 * @param lowLevelResults
+	 *            merge results as returned by
+	 *            {@link ResolveMerger#getMergeResults()}
+	 * @param failingPaths
+	 *            list of paths causing this merge to fail abnormally as
+	 *            returned by {@link ResolveMerger#getFailingPaths()}
+	 * @param description
+	 *            a user friendly description of the merge result
+	 */
+	public MergeResult(ObjectId newHead, ObjectId base,
+			ObjectId[] mergedCommits, MergeStatus mergeStatus,
+			MergeStrategy mergeStrategy,
+			Map<String, org.eclipse.jgit.merge.MergeResult<?>> lowLevelResults,
+			Map<String, MergeFailureReason> failingPaths, String description) {
 		this.newHead = newHead;
 		this.mergedCommits = mergedCommits;
 		this.base = base;
 		this.mergeStatus = mergeStatus;
 		this.mergeStrategy = mergeStrategy;
 		this.description = description;
+		this.failingPaths = failingPaths;
 		if (lowLevelResults != null)
 			for (Map.Entry<String, org.eclipse.jgit.merge.MergeResult<?>> result : lowLevelResults
 					.entrySet())
@@ -245,6 +281,8 @@ public class MergeResult {
 	 * @param lowLevelResult
 	 */
 	public void addConflict(String path, org.eclipse.jgit.merge.MergeResult<?> lowLevelResult) {
+		if (!lowLevelResult.containsConflicts())
+			return;
 		if (conflicts == null)
 			conflicts = new HashMap<String, int[][]>();
 		int nrOfConflicts = 0;
@@ -316,4 +354,15 @@ public class MergeResult {
 	public Map<String, int[][]> getConflicts() {
 		return conflicts;
 	}
+
+	/**
+	 * Returns a list of paths causing this merge to fail abnormally as returned
+	 * by {@link ResolveMerger#getFailingPaths()}
+	 *
+	 * @return the list of paths causing this merge to fail abnormally or
+	 *         <code>null</code> if no abnormal failure occurred
+	 */
+	public Map<String, MergeFailureReason> getFailingPaths() {
+		return failingPaths;
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/merge/ResolveMerger.java

@@ -637,6 +637,17 @@ public class ResolveMerger extends ThreeWayMerger {
 		return (failingPaths.size() == 0) ? null : failingPaths;
 	}
 
+	/**
+	 * Returns whether this merge failed abnormally (i.e. not because of a
+	 * conflict)
+	 *
+	 * @return <code>true</code> if an abnormal failure occurred,
+	 *         <code>false</code> otherwise
+	 */
+	public boolean failedAbnormally() {
+		return failingPaths.size() > 0;
+	}
+
 	/**
 	 * Sets the DirCache which shall be used by this merger. If the DirCache is
 	 * not set explicitly this merger will implicitly get and lock a default