diff --git a/Documentation/dev-buck.txt b/Documentation/dev-buck.txt
index f0f3345..89cd849 100644
--- a/Documentation/dev-buck.txt
+++ b/Documentation/dev-buck.txt
@@ -7,7 +7,7 @@
 
 There is currently no binary distribution of Buck, so it has to be manually
 built and installed.  Apache Ant is required.  Currently only Linux and Mac
-OS are supported.  Buck requires Python version 2.7 to be installed.
+OS are supported.
 
 Clone the git and build it:
 
@@ -50,6 +50,10 @@
 script from `./scripts/buck_completion.bash` in the buck project.  Refer
 to the script's header comments for installation instructions.
 
+== Prerequisites
+
+Buck requires Python version 2.7 to be installed. The Maven download toolchain
+requires `curl` to be installed.
 
 [[eclipse]]
 == Eclipse Integration
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/RevWalkPredicate.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/RevWalkPredicate.java
deleted file mode 100644
index 0947fae..0000000
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/RevWalkPredicate.java
+++ /dev/null
@@ -1,117 +0,0 @@
-// Copyright (C) 2013 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.gerrit.server.query.change;
-
-import com.google.gerrit.reviewdb.client.Change;
-import com.google.gerrit.reviewdb.client.PatchSet;
-import com.google.gerrit.reviewdb.client.Project;
-import com.google.gerrit.reviewdb.client.RevId;
-import com.google.gerrit.reviewdb.server.ReviewDb;
-import com.google.gerrit.server.git.GitRepositoryManager;
-import com.google.gerrit.server.query.OperatorPredicate;
-import com.google.gwtorm.server.OrmException;
-import com.google.inject.Provider;
-
-import org.eclipse.jgit.errors.RepositoryNotFoundException;
-import org.eclipse.jgit.lib.AnyObjectId;
-import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.revwalk.RevWalk;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.io.IOException;
-
-/**
- * Predicate which creates Repository, RevWalk objects and properly
- * closes them. Git based operators should extend this predicate.
- *
- */
-public abstract class RevWalkPredicate extends OperatorPredicate<ChangeData> {
-  private static final Logger log =
-      LoggerFactory.getLogger(RevWalkPredicate.class);
-
-  public static class Arguments {
-    public final PatchSet patchSet;
-    public final RevId revision;
-    public final AnyObjectId objectId;
-    public final Change change;
-    public final Project.NameKey projectName;
-
-    public Arguments(PatchSet patchSet,
-        RevId revision,
-        AnyObjectId objectId,
-        Change change,
-        Project.NameKey projectName) {
-      this.patchSet = patchSet;
-      this.revision = revision;
-      this.objectId = objectId;
-      this.change = change;
-      this.projectName = projectName;
-    }
-  }
-
-  public final Provider<ReviewDb> db;
-  public final GitRepositoryManager repoManager;
-
-  public RevWalkPredicate(Provider<ReviewDb> db,
-      GitRepositoryManager repoManager, String operator, String ref) {
-    super(operator, ref);
-    this.db = db;
-    this.repoManager = repoManager;
-  }
-
-  @Override
-  public boolean match(ChangeData object) throws OrmException {
-    final PatchSet patchSet = object.currentPatchSet();
-    if (patchSet == null) {
-      return false;
-    }
-
-    final RevId revision = patchSet.getRevision();
-    if (revision == null) {
-      return false;
-    }
-
-    final AnyObjectId objectId = ObjectId.fromString(revision.get());
-    if (objectId == null) {
-      return false;
-    }
-
-    Change change = object.change();
-    if (change == null) {
-      return false;
-    }
-
-    final Project.NameKey projectName = change.getProject();
-    if (projectName == null) {
-      return false;
-    }
-
-    Arguments args = new Arguments(patchSet, revision, objectId, change, projectName);
-
-    try (Repository repo = repoManager.openRepository(projectName);
-        RevWalk rw = new RevWalk(repo)) {
-      return match(repo, rw, args);
-    } catch (RepositoryNotFoundException e) {
-      log.error("Repository \"" + projectName.get() + "\" unknown.", e);
-    } catch (IOException e) {
-      log.error(projectName.get() + " cannot be read as a repository", e);
-    }
-    return false;
-  }
-
-  public abstract boolean match(Repository repo, RevWalk rw, Arguments args);
-}