From 1b107f06c19403a18e85eed1846ec8f443d5374b Mon Sep 17 00:00:00 2001
From: Alex Osborne <aosborne@nla.gov.au>
Date: Fri, 10 Jul 2026 14:54:19 +0900
Subject: [PATCH] BrowserProcessor: guard stop() against a partially failed
 start()

If start() throws after the proxy is started but before the browser
launches, stop() could NPE on the null fields.
---
 .../crawler/processor/BrowserProcessor.java   | 20 +++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/engine/src/main/java/org/archive/crawler/processor/BrowserProcessor.java b/engine/src/main/java/org/archive/crawler/processor/BrowserProcessor.java
index 297ef6f3..ea1e0f9b 100644
--- a/engine/src/main/java/org/archive/crawler/processor/BrowserProcessor.java
+++ b/engine/src/main/java/org/archive/crawler/processor/BrowserProcessor.java
@@ -109,15 +109,19 @@ public class BrowserProcessor extends Processor {
     public void stop() {
         if (!isRunning) return;
         super.stop();
-        try {
-            proxy.stop();
-        } catch (Exception e) {
-            logger.log(ERROR, "Error stopping proxy server", e);
+        if (proxy != null) {
+            try {
+                proxy.stop();
+            } catch (Exception e) {
+                logger.log(ERROR, "Error stopping proxy server", e);
+            }
         }
-        try {
-            webdriver.close();
-        } catch (Exception e) {
-            logger.log(ERROR, "Error closing WebDriverBiDi", e);
+        if (webdriver != null) {
+            try {
+                webdriver.close();
+            } catch (Exception e) {
+                logger.log(ERROR, "Error closing WebDriverBiDi", e);
+            }
         }
     }