From 2a07b98e9cfac77f9e1a4eacf7393e620a5aaf20 Mon Sep 17 00:00:00 2001
From: Jesse Glick <jglick@cloudbees.com>
Date: Wed, 20 Sep 2023 14:42:26 -0400
Subject: [PATCH] `StringIndexOutOfBoundsException` in `AbstractItem.getUrl`
 (#8481)

---
 core/src/main/java/hudson/model/AbstractItem.java    | 12 +++++++++---
 .../java/jenkins/widgets/BuildListTableTest.java     |  4 ++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/core/src/main/java/hudson/model/AbstractItem.java b/core/src/main/java/hudson/model/AbstractItem.java
index 92900e678445..ef9b97319053 100644
--- a/core/src/main/java/hudson/model/AbstractItem.java
+++ b/core/src/main/java/hudson/model/AbstractItem.java
@@ -555,9 +555,15 @@ public final String getUrl() {
                     View view = (View) last.getObject();
                     if (view.getOwner().getItemGroup() == getParent() && !view.isDefault()) {
                         // Showing something inside a view, so should use that as the base URL.
-                        String base = last.getUrl().substring(req.getContextPath().length() + 1) + '/';
-                        LOGGER.log(Level.FINER, "using {0}{1} for {2} from {3}", new Object[] {base, shortUrl, this, uri});
-                        return base + shortUrl;
+                        String prefix = req.getContextPath() + "/";
+                        String url = last.getUrl();
+                        if (url.startsWith(prefix)) {
+                            String base = url.substring(prefix.length()) + '/';
+                            LOGGER.log(Level.FINER, "using {0}{1} for {2} from {3} given {4}", new Object[] {base, shortUrl, this, uri, prefix});
+                            return base + shortUrl;
+                        } else {
+                            LOGGER.finer(() -> url + " does not start with " + prefix + " as expected");
+                        }
                     } else {
                         LOGGER.log(Level.FINER, "irrelevant {0} for {1} from {2}", new Object[] {view.getViewName(), this, uri});
                     }
diff --git a/test/src/test/java/jenkins/widgets/BuildListTableTest.java b/test/src/test/java/jenkins/widgets/BuildListTableTest.java
index ce53249e4c7c..e9a1b473e1ef 100644
--- a/test/src/test/java/jenkins/widgets/BuildListTableTest.java
+++ b/test/src/test/java/jenkins/widgets/BuildListTableTest.java
@@ -26,21 +26,25 @@
 
 import static org.junit.Assert.assertEquals;
 
+import hudson.model.AbstractItem;
 import hudson.model.FreeStyleProject;
 import hudson.model.ListView;
 import java.net.URI;
 import java.net.URL;
+import java.util.logging.Level;
 import org.htmlunit.html.HtmlAnchor;
 import org.htmlunit.html.HtmlPage;
 import org.junit.Rule;
 import org.junit.Test;
 import org.jvnet.hudson.test.Issue;
 import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.LoggerRule;
 import org.jvnet.hudson.test.MockFolder;
 
 public class BuildListTableTest {
 
     @Rule public JenkinsRule r = new JenkinsRule();
+    @Rule public LoggerRule logging = new LoggerRule().record(AbstractItem.class, Level.FINER);
 
     @Issue("JENKINS-19310")
     @Test public void linksFromFolders() throws Exception {