Merge "Add reset() to AbstractTreeIterator API"

org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheIterator.java

@@ -159,6 +159,15 @@ public class DirCacheIterator extends AbstractTreeIterator {
 		return 0;
 	}
 
+	@Override
+	public void reset() {
+		if (!first()) {
+			ptr = treeStart;
+			if (!eof())
+				parseEntry();
+		}
+	}
+
 	@Override
 	public boolean first() {
 		return ptr == treeStart;

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

@@ -496,6 +496,22 @@ public abstract class AbstractTreeIterator {
 		return createSubtreeIterator(reader);
 	}
 
+	/**
+	 * Position this iterator on the first entry.
+	 *
+	 * The default implementation of this method uses {@code back(1)} until
+	 * {@code first()} is true. This is most likely not the most efficient
+	 * method of repositioning the iterator to its first entry, so subclasses
+	 * are strongly encouraged to override the method.
+	 *
+	 * @throws CorruptObjectException
+	 *             the tree is invalid.
+	 */
+	public void reset() throws CorruptObjectException {
+		while (!first())
+			back(1);
+	}
+
 	/**
 	 * Is this tree iterator positioned on its first entry?
 	 * <p>

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

@@ -243,6 +243,12 @@ public class CanonicalTreeParser extends AbstractTreeIterator {
 		return nextPtr - Constants.OBJECT_ID_LENGTH;
 	}
 
+	@Override
+	public void reset() {
+		if (!first())
+			reset(raw);
+	}
+
 	@Override
 	public boolean first() {
 		return currPtr == 0;

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

@@ -107,6 +107,11 @@ public class EmptyTreeIterator extends AbstractTreeIterator {
 		return 0;
 	}
 
+	@Override
+	public void reset() {
+		// Do nothing.
+	}
+
 	@Override
 	public boolean first() {
 		return true;

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

@@ -332,6 +332,15 @@ public abstract class WorkingTreeIterator extends AbstractTreeIterator {
 		return 0;
 	}
 
+	@Override
+	public void reset() {
+		if (!first()) {
+			ptr = 0;
+			if (!eof())
+				parseEntry();
+		}
+	}
+
 	@Override
 	public boolean first() {
 		return ptr == 0;