From 70b1fd40efe0f15c8797851700a24995c6b242bb Mon Sep 17 00:00:00 2001
From: Lachlan Roberts <lachlan@webtide.com>
Date: Tue, 10 Oct 2023 11:26:55 +1100
Subject: [PATCH] fix infinite recursion in server dump with Path

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>
---
 .../jetty/util/component/Dumpable.java        | 10 ++++-
 .../tests/distribution/DemoModulesTests.java  | 44 +++++++++++++++++++
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/component/Dumpable.java b/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/component/Dumpable.java
index 6b41542a7e5..7c728f5a36f 100644
--- a/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/component/Dumpable.java
+++ b/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/component/Dumpable.java
@@ -15,10 +15,12 @@ package org.eclipse.jetty.util.component;
 
 import java.io.IOException;
 import java.lang.reflect.Array;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.Objects;
 import java.util.stream.Stream;
 
 import org.eclipse.jetty.util.StringUtil;
@@ -155,7 +157,8 @@ public interface Dumpable
         {
             dumpContainer(out, indent, (Container)object, extras == 0);
         }
-        if (object instanceof Iterable)
+        // Dump an Iterable Path because it may contain itself.
+        if (object instanceof Iterable && !(object instanceof Path))
         {
             dumpIterable(out, indent, (Iterable<?>)object, extras == 0);
         }
@@ -231,12 +234,15 @@ public interface Dumpable
             }
         }
     }
-    
+
     static void dumpIterable(Appendable out, String indent, Iterable<?> iterable, boolean last) throws IOException
     {
         for (Iterator i = iterable.iterator(); i.hasNext(); )
         {
             Object item = i.next();
+            // Safety net to stop iteration when an Iterable contains itself e.g. Path.
+            if (Objects.equals(item, iterable))
+                return;
             String nextIndent = indent + ((i.hasNext() || !last) ? "|  " : "   ");
             out.append(indent).append("+: ");
             if (item instanceof Dumpable)
diff --git a/tests/test-distribution/test-distribution-common/src/test/java/org/eclipse/jetty/tests/distribution/DemoModulesTests.java b/tests/test-distribution/test-distribution-common/src/test/java/org/eclipse/jetty/tests/distribution/DemoModulesTests.java
index 7e0bf3f6063..24cc52e14a2 100644
--- a/tests/test-distribution/test-distribution-common/src/test/java/org/eclipse/jetty/tests/distribution/DemoModulesTests.java
+++ b/tests/test-distribution/test-distribution-common/src/test/java/org/eclipse/jetty/tests/distribution/DemoModulesTests.java
@@ -652,4 +652,48 @@ public class DemoModulesTests extends AbstractJettyHomeTest
             }
         }
     }
+
+    @ParameterizedTest
+    @MethodSource("provideEnvironmentsToTest")
+    public void testJettyDemo(String env) throws Exception
+    {
+        Path jettyBase = newTestJettyBaseDirectory();
+        String jettyVersion = System.getProperty("jettyVersion");
+        JettyHomeTester distribution = JettyHomeTester.Builder.newInstance()
+            .jettyVersion(jettyVersion)
+            .jettyBase(jettyBase)
+            .build();
+
+        int httpPort = distribution.freePort();
+        int sslPort = distribution.freePort();
+
+        String[] argsConfig = {
+            "--add-modules=http," + toEnvironment("demos", env)
+        };
+
+        try (JettyHomeTester.Run runConfig = distribution.start(argsConfig))
+        {
+            assertTrue(runConfig.awaitFor(START_TIMEOUT, TimeUnit.SECONDS));
+            assertEquals(0, runConfig.getExitValue());
+
+            String[] argsStart = {
+                "jetty.http.port=" + httpPort,
+                "jetty.ssl.port=" + sslPort,
+                "jetty.server.dumpAfterStart=true"
+            };
+
+            try (JettyHomeTester.Run runStart = distribution.start(argsStart))
+            {
+                assertTrue(runStart.awaitConsoleLogsFor("Started oejs.Server@", START_TIMEOUT, TimeUnit.SECONDS));
+                startHttpClient();
+                String baseURI = "http://localhost:%d/%s-test".formatted(httpPort, env);
+
+                ContentResponse response = client.POST(baseURI + "/dump/info").send();
+                assertEquals(HttpStatus.OK_200, response.getStatus(), new ResponseDetails(response));
+                assertThat(response.getContentAsString(), containsString("Dump Servlet"));
+                assertThat(response.getContentAsString(), containsString("context-override-example:&nbsp;</th><td>a context value"));
+            }
+        }
+    }
+
 }