From 86114e04d0099c88480b37452ad9af895dc5dea6 Mon Sep 17 00:00:00 2001
From: Sokwhan Huh <sokwhan@google.com>
Date: Mon, 7 Aug 2023 11:20:00 -0700
Subject: [PATCH] Prevent reloading of default message instance when an error
 is encountered

This fixes https://github.com/google/cel-java/issues/119

PiperOrigin-RevId: 554536199
---
 .../cel/common/internal/DefaultInstanceMessageFactory.java  | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/common/src/main/java/dev/cel/common/internal/DefaultInstanceMessageFactory.java b/common/src/main/java/dev/cel/common/internal/DefaultInstanceMessageFactory.java
index 75aa7a21e..131b1cf10 100644
--- a/common/src/main/java/dev/cel/common/internal/DefaultInstanceMessageFactory.java
+++ b/common/src/main/java/dev/cel/common/internal/DefaultInstanceMessageFactory.java
@@ -196,16 +196,18 @@ private boolean hasConflictingClassName(FileDescriptor file, String name) {
   private static final class LazyGeneratedMessageDefaultInstance {
     private final String fullClassName;
     private volatile Message defaultInstance = null;
+    private volatile boolean loaded = false;
 
     public LazyGeneratedMessageDefaultInstance(String fullClassName) {
       this.fullClassName = fullClassName;
     }
 
     public Message getDefaultInstance() {
-      if (defaultInstance == null) {
+      if (!loaded) {
         synchronized (this) {
-          if (defaultInstance == null) {
+          if (!loaded) {
             loadDefaultInstance();
+            loaded = true;
           }
         }
       }