Revert "Adds FilteredRevCommit that can overwrites its parents in the DAG."

This reverts commit ceb51a5e0e9db166e572ea7cd362795b4662b0cd.

Reason for revert: The change in https://git.eclipse.org/r/c/jgit/jgit/+/194354 broke the egit test [1]. Calling c.getShortMessage() causes an NPE.

[1] https://ci.eclipse.org/egit/job/egit.gerrit/2711/

Change-Id: I411565b6eaa0bbb562cc1c8a355942ff09fd29bc

2 files changed, 3 insertions, 118 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 be6e57fd5f..0000000000
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/FilteredRevCommit.java
+++ /dev/null
@@ -1,115 +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;
-
-import org.eclipse.jgit.lib.ObjectId;
-
-/** A filtered commit reference that overrides its parent in the DAG. */
-public class FilteredRevCommit extends RevCommit {
-	private RevCommit[] overriddenParents;
-
-	/**
-	 * Create a new commit reference for the given id.
-	 *
-	 * @param id
-	 *            object name for the commit.
-	 */
-	public FilteredRevCommit(ObjectId id) {
-		this(id, NO_PARENTS);
-	}
-
-	/**
-	 * 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) {
-		this(commit.getId(), parents);
-	}
-
-	/**
-	 * Create a new commit reference wrapping an underlying commit reference.
-	 *
-	 * @param id
-	 *            object name for the commit.
-	 * @param parents
-	 *            overridden parents for the commit
-	 */
-	public FilteredRevCommit(ObjectId id, RevCommit... parents) {
-		super(id);
-		this.overriddenParents = 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/RewriteGenerator.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java
index 3318a97a3f..2c88bb872e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteGenerator.java
@@ -79,9 +79,9 @@ class RewriteGenerator extends Generator {
 			final RevCommit newp = rewrite(oldp);
 			if (firstParent) {
 				if (newp == null) {
-					c = new FilteredRevCommit(c.getId());
+					c.parents = RevCommit.NO_PARENTS;
 				} else {
-					c = new FilteredRevCommit(c.getId(), newp);
+					c.parents = new RevCommit[] { newp };
 				}
 				return c;
 			}
@@ -91,7 +91,7 @@ class RewriteGenerator extends Generator {
 			}
 		}
 		if (rewrote) {
-			c = new FilteredRevCommit(c.getId(), cleanup(pList));
+			c.parents = cleanup(pList);
 		}
 		return c;
 	}