From 1717a71b0c0dddcdfd69c230226b6c7b5ab268db Mon Sep 17 00:00:00 2001
From: George Gensure <ggensure@uber.com>
Date: Thu, 11 Apr 2019 14:01:28 -0400
Subject: [PATCH] Sort DirectoryNode children to ensure validity.

InputTree will create DirectoryNodes with non-sequential additions of
directory children. These must be maintained in order for representation
within remote Directory messages (and to properly compute action keys).
---
 .../build/lib/remote/merkletree/InputTree.java        | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/google/devtools/build/lib/remote/merkletree/InputTree.java b/src/main/java/com/google/devtools/build/lib/remote/merkletree/InputTree.java
index 9e1c7aad5008d4..749ab278f5d70d 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/merkletree/InputTree.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/merkletree/InputTree.java
@@ -16,6 +16,7 @@
 import build.bazel.remote.execution.v2.Digest;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
+import com.google.common.collect.Sets;
 import com.google.devtools.build.lib.actions.ActionInput;
 import com.google.devtools.build.lib.actions.ActionInputHelper;
 import com.google.devtools.build.lib.actions.FileArtifactValue;
@@ -34,6 +35,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.SortedMap;
+import java.util.SortedSet;
 import java.util.TreeMap;
 
 /**
@@ -46,7 +48,7 @@ interface Visitor {
     void visitDirectory(PathFragment dirname, List<FileNode> files, List<DirectoryNode> dirs);
   }
 
-  abstract static class Node {
+  abstract static class Node implements Comparable<Node> {
     private final String pathSegment;
 
     Node(String pathSegment) {
@@ -57,6 +59,11 @@ String getPathSegment() {
       return pathSegment;
     }
 
+    @Override
+    public int compareTo(Node other) {
+      return pathSegment.compareTo(other.pathSegment);
+    }
+
     @Override
     public int hashCode() {
       return pathSegment.hashCode();
@@ -108,7 +115,7 @@ public boolean equals(Object o) {
   }
 
   static class DirectoryNode extends Node {
-    private final List<Node> children = new ArrayList<>();
+    private final SortedSet<Node> children = Sets.newTreeSet();
 
     DirectoryNode(String pathSegment) {
       super(pathSegment);