Fix RecursiveMerger's internal use of merge to find a merge base

When RecursiveMerger tried to determine a common base tree it was
recursively tried to merge multiple common bases. But these intermediate
merges which have just been done to determine a single common base for
the final merge already filled some important fields (toBeCheckedOut,
toBeDeleted, ...). These side effects of the intermediate merges led to
wrong results of the final merge. One symptom was that after a recursive
merge which should be succesful you could still see leftover files in
the worktree: files which existed in the (virtual) common base but which
don't exist anymore in the branches to be merged.

The solution is easy: Clear the appropriate fields after common base
determination and start the final merge with a clean state.

Change-Id: I644ea9e1cb15360f7901bc0483cdb9286308c226
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

2 files changed, 9 insertions, 0 deletions

diff --git a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/JGitTestUtil.java b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/JGitTestUtil.java
index 1079d98439..136c64726f 100644
--- a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/JGitTestUtil.java
+++ b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/JGitTestUtil.java
@@ -229,6 +229,11 @@ public abstract class JGitTestUtil {
 		return read(file);
 	}
 
+	public static boolean check(final Repository db, final String name) {
+		File file = new File(db.getWorkTree(), name);
+		return file.exists();
+	}
+
 	public static void deleteTrashFile(final Repository db,
 			final String name) throws IOException {
 		File path = new File(db.getWorkTree(), name);
diff --git a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/RepositoryTestCase.java b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/RepositoryTestCase.java
index c1e0a2dcf3..bc225cc017 100644
--- a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/RepositoryTestCase.java
+++ b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/RepositoryTestCase.java
@@ -119,6 +119,10 @@ public abstract class RepositoryTestCase extends LocalDiskRepositoryTestCase {
 		return JGitTestUtil.read(db, name);
 	}
 
+	protected boolean check(final String name) {
+		return JGitTestUtil.check(db, name);
+	}
+
 	protected void deleteTrashFile(final String name) throws IOException {
 		JGitTestUtil.deleteTrashFile(db, name);
 	}