Handle fatal Errors in WebSocketClient read loop

src/main/java/org/java_websocket/client/WebSocketClient.java

@@ -565,6 +565,13 @@ public void run() {
       // this catch case covers internal errors only and indicates a bug in this websocket implementation
       onError(e);
       engine.closeConnection(CloseFrame.ABNORMAL_CLOSE, e.getMessage());
+    } catch (VirtualMachineError | ThreadDeath | LinkageError e) {
+      // Fatal Errors rethrown by WebSocketImpl#decodeFrames must surface via onError and
+      // close the connection instead of silently terminating the connect/read thread.
+      // See https://github.com/TooTallNate/Java-WebSocket/issues/1460
+      onError(new Exception(e));
+      engine.closeConnection(CloseFrame.UNEXPECTED_CONDITION,
+          "Got error " + e.getClass().getName());
     }
   }
 

src/test/java/org/java_websocket/issues/Issue1460Test.java

@@ -0,0 +1,148 @@
+package org.java_websocket.issues;
+
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.java_websocket.WebSocket;
+import org.java_websocket.client.WebSocketClient;
+import org.java_websocket.drafts.Draft;
+import org.java_websocket.drafts.Draft_6455;
+import org.java_websocket.extensions.IExtension;
+import org.java_websocket.framing.CloseFrame;
+import org.java_websocket.framing.Framedata;
+import org.java_websocket.handshake.ClientHandshake;
+import org.java_websocket.handshake.ServerHandshake;
+import org.java_websocket.server.WebSocketServer;
+import org.java_websocket.util.SocketUtil;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Regression test for #1460: a fatal Error (VirtualMachineError / ThreadDeath / LinkageError)
+ * rethrown by WebSocketImpl#decodeFrames must reach onError and close the client connection
+ * instead of silently killing the connect/read thread with no callback and no cleanup.
+ */
+public class Issue1460Test {
+
+  /**
+   * Draft that emulates a fatal Error during frame decoding, i.e. the trio
+   * WebSocketImpl#decodeFrames rethrows.
+   */
+  private static class FatalErrorDraft extends Draft_6455 {
+    @Override
+    public List<Framedata> translateFrame(ByteBuffer buffer) {
+      throw new LinkageError("simulated fatal error during frame processing");
+    }
+
+    @Override
+    public Draft copyInstance() {
+      ArrayList<IExtension> newExtensions = new ArrayList<>();
+      for (IExtension knownExtension : getKnownExtensions()) {
+        newExtensions.add(knownExtension.copyInstance());
+      }
+      ArrayList<org.java_websocket.protocols.IProtocol> newProtocols = new ArrayList<>();
+      for (org.java_websocket.protocols.IProtocol knownProtocol : getKnownProtocols()) {
+        newProtocols.add(knownProtocol.copyInstance());
+      }
+      return new FatalErrorDraft(newExtensions, newProtocols, getMaxFrameSize());
+    }
+
+    FatalErrorDraft(List<IExtension> inputExtensions,
+        List<org.java_websocket.protocols.IProtocol> inputProtocols, int inputMaxFrameSize) {
+      super(inputExtensions, inputProtocols, inputMaxFrameSize);
+    }
+
+    FatalErrorDraft() {
+      super();
+    }
+  }
+
+  @Test
+  @Timeout(value = 10, unit = TimeUnit.SECONDS)
+  public void testFatalErrorTriggersOnErrorAndClose() throws InterruptedException {
+    int port = SocketUtil.getAvailablePort();
+    final CountDownLatch startLatch = new CountDownLatch(1);
+    final CountDownLatch errorLatch = new CountDownLatch(1);
+    final CountDownLatch closeLatch = new CountDownLatch(1);
+    final AtomicReference<Throwable> capturedError = new AtomicReference<>();
+    final AtomicInteger capturedCode = new AtomicInteger(-1);
+
+    WebSocketServer server = new WebSocketServer(new InetSocketAddress(port)) {
+      @Override
+      public void onOpen(WebSocket conn, ClientHandshake handshake) {
+        conn.send("trigger");
+      }
+
+      @Override
+      public void onClose(WebSocket conn, int code, String reason, boolean remote) {
+      }
+
+      @Override
+      public void onMessage(WebSocket conn, String message) {
+      }
+
+      @Override
+      public void onMessage(WebSocket conn, ByteBuffer message) {
+      }
+
+      @Override
+      public void onError(WebSocket conn, Exception ex) {
+        ex.printStackTrace();
+      }
+
+      @Override
+      public void onStart() {
+        startLatch.countDown();
+      }
+    };
+
+    WebSocketClient client = new WebSocketClient(
+        URI.create("ws://localhost:" + port), new FatalErrorDraft()) {
+      @Override
+      public void onOpen(ServerHandshake handshakedata) {
+      }
+
+      @Override
+      public void onMessage(String message) {
+      }
+
+      @Override
+      public void onClose(int code, String reason, boolean remote) {
+        capturedCode.set(code);
+        closeLatch.countDown();
+      }
+
+      @Override
+      public void onError(Exception ex) {
+        capturedError.set(ex);
+        errorLatch.countDown();
+      }
+    };
+
+    server.start();
+    assertTrue(startLatch.await(5, TimeUnit.SECONDS), "server should start");
+    client.connectBlocking();
+
+    try {
+      assertTrue(errorLatch.await(5, TimeUnit.SECONDS),
+          "onError must be invoked for a fatal Error");
+      assertTrue(closeLatch.await(5, TimeUnit.SECONDS),
+          "onClose must be invoked for a fatal Error");
+      assertTrue(capturedError.get().getCause() instanceof LinkageError,
+          "onError must wrap the fatal Error");
+      assertEquals(CloseFrame.UNEXPECTED_CONDITION, capturedCode.get());
+    } finally {
+      server.stop();
+    }
+  }
+}