Revert "Adds FilteredRevCommit that can overwrites its parents in the

DAG."

This reverts commit 6297491e8adb85e43d60ffe75fb71f335e733449.

This is done as a quick fix for the failure of egit tests caused by  the
introduction of FilteredRevCommit.

Bug: 580690
Change-Id: Ia6b651dd11b0a4b02d5e52247eb4bf13adf94e27

3 files changed, 8 insertions, 142 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FilteredRevCommit.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FilteredRevCommit.java
deleted file mode 100644
index 16beac3903..0000000000
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FilteredRevCommit.java
+++ /dev/null
@@ -1,95 +0,0 @@
-/*
- * Copyright (C) 2022, Google LLC.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Distribution License v. 1.0 which is available at
- * https://www.eclipse.org/org/documents/edl-v10.php.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-package org.eclipse.jgit.revwalk;
-
-/**
- * A filtered commit reference that overrides its parent in the DAG.
- *
- * @since 6.3
- */
-public class FilteredRevCommit extends RevCommit {
-	private RevCommit[] overriddenParents;
-
-	/**
-	 * Create a new commit reference wrapping an underlying commit reference.
-	 *
-	 * @param commit
-	 *            commit that is being wrapped
-	 */
-	public FilteredRevCommit(RevCommit commit) {
-		this(commit, NO_PARENTS);
-	}
-
-	/**
-	 * Create a new commit reference wrapping an underlying commit reference.
-	 *
-	 * @param commit
-	 *            commit that is being wrapped
-	 * @param parents
-	 *            overridden parents for the commit
-	 */
-	public FilteredRevCommit(RevCommit commit, RevCommit... parents) {
-		super(commit);
-		this.overriddenParents = parents;
-		this.parents = NO_PARENTS;
-	}
-
-	/**
-	 * Update parents on the commit
-	 *
-	 * @param overriddenParents
-	 *            parents to be overwritten
-	 */
-	public void setParents(RevCommit... overriddenParents) {
-		this.overriddenParents = overriddenParents;
-	}
-
-	/**
-	 * Get the number of parent commits listed in this commit.
-	 *
-	 * @return number of parents; always a positive value but can be 0 if it has
-	 *         no parents.
-	 */
-	@Override
-	public int getParentCount() {
-		return overriddenParents.length;
-	}
-
-	/**
-	 * Get the nth parent from this commit's parent list.
-	 *
-	 * @param nth
-	 *            parent index to obtain. Must be in the range 0 through
-	 *            {@link #getParentCount()}-1.
-	 * @return the specified parent.
-	 * @throws java.lang.ArrayIndexOutOfBoundsException
-	 *             an invalid parent index was specified.
-	 */
-	@Override
-	public RevCommit getParent(int nth) {
-		return overriddenParents[nth];
-	}
-
-	/**
-	 * Obtain an array of all parents (<b>NOTE - THIS IS NOT A COPY</b>).
-	 *
-	 * <p>
-	 * This method is exposed only to provide very fast, efficient access to
-	 * this commit's parent list. Applications relying on this list should be
-	 * very careful to ensure they do not modify its contents during their use
-	 * of it.
-	 *
-	 * @return the array of parents.
-	 */
-	@Override
-	public RevCommit[] getParents() {
-		return overriddenParents;
-	}
-}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java
index a7c21e3f13..6b644cef90 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevCommit.java
@@ -114,7 +114,7 @@ public class RevCommit extends RevObject {
 	 *
 	 * @since 6.3
 	 */
-	RevCommit[] parents;
+	protected RevCommit[] parents;
 
 	int commitTime; // An int here for performance, overflows in 2038
 
@@ -132,22 +132,6 @@ public class RevCommit extends RevObject {
 		super(id);
 	}
 
-	/**
-	 * Create a new commit reference.
-	 *
-	 * @param orig
-	 *            commit to be copied from.
-	 */
-	RevCommit(RevCommit orig) {
-		super(orig.getId());
-		this.buffer = orig.buffer;
-		this.commitTime = orig.commitTime;
-		this.flags = orig.flags;
-		this.parents = orig.parents;
-		this.tree = orig.tree;
-		this.inDegree = orig.inDegree;
-	}
-
 	@Override
 	void parseHeaders(RevWalk walk) throws MissingObjectException,
 			IncorrectObjectTypeException, IOException {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java
index 9ec331b697..2c88bb872e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java
@@ -11,8 +11,6 @@
 package org.eclipse.jgit.revwalk;
 
 import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
 
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -40,13 +38,10 @@ class RewriteGenerator extends Generator {
 
 	private final FIFORevQueue pending;
 
-	private final Map<RevCommit, FilteredRevCommit> transformedCommits;
-
 	RewriteGenerator(Generator s) {
 		super(s.firstParent);
 		source = s;
 		pending = new FIFORevQueue(s.firstParent);
-		transformedCommits = new HashMap<>();
 	}
 
 	@Override
@@ -63,10 +58,10 @@ class RewriteGenerator extends Generator {
 	@Override
 	RevCommit next() throws MissingObjectException,
 			IncorrectObjectTypeException, IOException {
-		FilteredRevCommit c = (FilteredRevCommit) pending.next();
+		RevCommit c = pending.next();
 
 		if (c == null) {
-			c = transform(source.next());
+			c = source.next();
 			if (c == null) {
 				// We are done: Both the source generator and our internal list
 				// are completely exhausted.
@@ -84,9 +79,9 @@ class RewriteGenerator extends Generator {
 			final RevCommit newp = rewrite(oldp);
 			if (firstParent) {
 				if (newp == null) {
-					c.setParents(RevCommit.NO_PARENTS);
+					c.parents = RevCommit.NO_PARENTS;
 				} else {
-					c.setParents(newp);
+					c.parents = new RevCommit[] { newp };
 				}
 				return c;
 			}
@@ -96,7 +91,7 @@ class RewriteGenerator extends Generator {
 			}
 		}
 		if (rewrote) {
-			c.setParents(cleanup(pList));
+			c.parents = cleanup(pList);
 		}
 		return c;
 	}
@@ -116,7 +111,7 @@ class RewriteGenerator extends Generator {
 		for (RevCommit parent : c.getParents()) {
 			while ((parent.flags & RevWalk.TREE_REV_FILTER_APPLIED) == 0) {
 
-				FilteredRevCommit n = transform(source.next());
+				RevCommit n = source.next();
 
 				if (n != null) {
 					pending.add(n);
@@ -135,8 +130,6 @@ class RewriteGenerator extends Generator {
 			IncorrectObjectTypeException, IOException {
 		for (;;) {
 
-			p = transform(p);
-
 			if (p.getParentCount() > 1) {
 				// This parent is a merge, so keep it.
 				//
@@ -165,25 +158,9 @@ class RewriteGenerator extends Generator {
 			}
 
 			applyFilterToParents(p.getParent(0));
-			p = transform(p.getParent(0));
-
-		}
-	}
+			p = p.getParent(0);
 
-	private FilteredRevCommit transform(RevCommit c) {
-		if (c == null) {
-			return null;
 		}
-
-		if (c instanceof FilteredRevCommit) {
-			return (FilteredRevCommit) c;
-		}
-
-		if (!transformedCommits.containsKey(c)) {
-			transformedCommits.put(c, new FilteredRevCommit(c, c.getParents()));
-		}
-
-		return transformedCommits.get(c);
 	}
 
 	private RevCommit[] cleanup(RevCommit[] oldList) {