Revert "StartGenerator: Fix parent rewrite with non-default RevFilter"

This reverts commit db5ce6b5c24408ae27eb6fa0b6289d51b129baeb.

Reason to revert: This change utilizes the RewriteGenerator even in
absence of a path, making the walk lengthy.

Change-Id: I5ffa6e8fead328191348c1e46828bf8c75ae1e42

4 files changed, 24 insertions, 123 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterTest.java
index f67a623ff6..298facfd15 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterTest.java
@@ -21,7 +21,6 @@ import org.junit.Test;
 
 public class TreeRevFilterTest extends RevWalkTestCase {
 	private RevFilter treeRevFilter() {
-		rw.setRewriteParents(false);
 		return new TreeRevFilter(rw, TreeFilter.ANY_DIFF);
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterWithRewriteParentsTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterWithRewriteParentsTest.java
deleted file mode 100644
index 100f2e4164..0000000000
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/TreeRevFilterWithRewriteParentsTest.java
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
- * Copyright (C) 2023, Google LLC and others
- *
- * 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 static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-
-import org.eclipse.jgit.revwalk.filter.RevFilter;
-import org.eclipse.jgit.treewalk.filter.TreeFilter;
-import org.junit.Test;
-
-public class TreeRevFilterWithRewriteParentsTest extends RevWalkTestCase {
-	private RevFilter treeRevFilter() {
-		rw.setRewriteParents(true);
-		return new TreeRevFilter(rw, TreeFilter.ANY_DIFF);
-	}
-
-	@Test
-	public void testStringOfPearls_FilePath1()
-			throws Exception {
-		RevCommit a = commit(tree(file("d/f", blob("a"))));
-		RevCommit b = commit(tree(file("d/f", blob("a"))), a);
-		RevCommit c = commit(tree(file("d/f", blob("b"))), b);
-		rw.setRevFilter(treeRevFilter());
-		markStart(c);
-
-		assertCommit(c, rw.next());
-		assertEquals(1, c.getParentCount());
-		assertCommit(a, c.getParent(0));
-
-		assertCommit(a, rw.next()); // b was skipped
-		assertEquals(0, a.getParentCount());
-		assertNull(rw.next());
-	}
-
-	@Test
-	public void testStringOfPearls_FilePath2() throws Exception {
-		RevCommit a = commit(tree(file("d/f", blob("a"))));
-		RevCommit b = commit(tree(file("d/f", blob("a"))), a);
-		RevCommit c = commit(tree(file("d/f", blob("b"))), b);
-		RevCommit d = commit(tree(file("d/f", blob("b"))), c);
-		rw.setRevFilter(treeRevFilter());
-		markStart(d);
-
-		// d was skipped
-		assertCommit(c, rw.next());
-		assertEquals(1, c.getParentCount());
-		assertCommit(a, c.getParent(0));
-
-		// b was skipped
-		assertCommit(a, rw.next());
-		assertEquals(0, a.getParentCount());
-		assertNull(rw.next());
-	}
-
-	@Test
-	public void testStringOfPearls_DirPath2() throws Exception {
-		RevCommit a = commit(tree(file("d/f", blob("a"))));
-		RevCommit b = commit(tree(file("d/f", blob("a"))), a);
-		RevCommit c = commit(tree(file("d/f", blob("b"))), b);
-		RevCommit d = commit(tree(file("d/f", blob("b"))), c);
-		rw.setRevFilter(treeRevFilter());
-		markStart(d);
-
-		// d was skipped
-		assertCommit(c, rw.next());
-		assertEquals(1, c.getParentCount());
-		assertCommit(a, c.getParent(0));
-
-		// b was skipped
-		assertCommit(a, rw.next());
-		assertEquals(0, a.getParentCount());
-		assertNull(rw.next());
-	}
-
-	@Test
-	public void testStringOfPearls_FilePath3() throws Exception {
-		RevCommit a = commit(tree(file("d/f", blob("a"))));
-		RevCommit b = commit(tree(file("d/f", blob("a"))), a);
-		RevCommit c = commit(tree(file("d/f", blob("b"))), b);
-		RevCommit d = commit(tree(file("d/f", blob("b"))), c);
-		RevCommit e = commit(tree(file("d/f", blob("b"))), d);
-		RevCommit f = commit(tree(file("d/f", blob("b"))), e);
-		RevCommit g = commit(tree(file("d/f", blob("b"))), f);
-		RevCommit h = commit(tree(file("d/f", blob("b"))), g);
-		RevCommit i = commit(tree(file("d/f", blob("c"))), h);
-		rw.setRevFilter(treeRevFilter());
-		markStart(i);
-
-		assertCommit(i, rw.next());
-		assertEquals(1, i.getParentCount());
-		assertCommit(c, i.getParent(0));
-
-		// h..d was skipped
-		assertCommit(c, rw.next());
-		assertEquals(1, c.getParentCount());
-		assertCommit(a, c.getParent(0));
-
-		// b was skipped
-		assertCommit(a, rw.next());
-		assertEquals(0, a.getParentCount());
-		assertNull(rw.next());
-	}
-}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/StartGenerator.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/StartGenerator.java
index 61a91e70dc..6854b6083d 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/StartGenerator.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/StartGenerator.java
@@ -98,14 +98,14 @@ class StartGenerator extends Generator {
 		} else {
 			pending = RevWalk.newDateRevQueue(q);
 		}
-		if (rf != RevFilter.ALL && w.getRewriteParents()) {
-			pendingOutputType |= HAS_REWRITE | NEEDS_REWRITE;
-		}
 		if (tf != TreeFilter.ALL) {
+			int rewriteFlag;
 			if (w.getRewriteParents()) {
 				pendingOutputType |= HAS_REWRITE | NEEDS_REWRITE;
-			}
-			rf = AndRevFilter.create(new TreeRevFilter(w, tf), rf);
+				rewriteFlag = RevWalk.REWRITE;
+			} else
+				rewriteFlag = 0;
+			rf = AndRevFilter.create(new TreeRevFilter(w, tf, rewriteFlag), rf);
 		}
 
 		walker.queue = q;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/TreeRevFilter.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/TreeRevFilter.java
index 4085954638..43571a6868 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/TreeRevFilter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/TreeRevFilter.java
@@ -60,8 +60,21 @@ public class TreeRevFilter extends RevFilter {
 	 * Create a {@link org.eclipse.jgit.revwalk.filter.RevFilter} from a
 	 * {@link org.eclipse.jgit.treewalk.filter.TreeFilter}.
 	 *
-	 * When revWalk's rewrite parent flag is set, it creates a filter for the
-	 * first phase of a parent-rewriting limited revision walk.
+	 * @param walker
+	 *            walker used for reading trees.
+	 * @param t
+	 *            filter to compare against any changed paths in each commit. If
+	 *            a {@link org.eclipse.jgit.revwalk.FollowFilter}, will be
+	 *            replaced with a new filter following new paths after a rename.
+	 * @since 3.5
+	 */
+	public TreeRevFilter(RevWalk walker, TreeFilter t) {
+		this(walker, t, 0);
+	}
+
+	/**
+	 * Create a filter for the first phase of a parent-rewriting limited
+	 * revision walk.
 	 * <p>
 	 * This filter is ANDed to evaluate before all other filters and ties the
 	 * configured {@link TreeFilter} into the revision walking process.
@@ -78,13 +91,14 @@ public class TreeRevFilter extends RevFilter {
 	 *            filter to compare against any changed paths in each commit. If
 	 *            a {@link FollowFilter}, will be replaced with a new filter
 	 *            following new paths after a rename.
-	 * @since 3.5
+	 * @param rewriteFlag
+	 *            flag to color commits to be removed from the simplified DAT.
 	 */
-	public TreeRevFilter(RevWalk walker, TreeFilter t) {
+	TreeRevFilter(RevWalk walker, TreeFilter t, int rewriteFlag) {
 		pathFilter = new TreeWalk(walker.reader);
 		pathFilter.setFilter(t);
 		pathFilter.setRecursive(t.shouldBeRecursive());
-		this.rewriteFlag = walker.getRewriteParents() ? RevWalk.REWRITE : 0;
+		this.rewriteFlag = rewriteFlag;
 	}
 
 	@Override