Fixes #2518 - How to handle 100-continue responses that don't fire onComplete callback.

HttpClient was confused by servers that responded
with two 100 Continue in the same HTTP conversation.

Now, whether the 100 Continue response has been handled
already is stored per-request, not per-conversation.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>

jetty-client/src/main/java/org/eclipse/jetty/client/ContinueProtocolHandler.java

@@ -54,8 +54,7 @@ public class ContinueProtocolHandler implements ProtocolHandler
     {
         boolean is100 = response.getStatus() == HttpStatus.CONTINUE_100;
         boolean expect100 = request.getHeaders().contains(HttpHeader.EXPECT, HttpHeaderValue.CONTINUE.asString());
-        HttpConversation conversation = ((HttpRequest)request).getConversation();
-        boolean handled100 = conversation.getAttribute(ATTRIBUTE) != null;
+        boolean handled100 = request.getAttributes().containsKey(ATTRIBUTE);
         return (is100 || expect100) && !handled100;
     }
 
@@ -81,7 +80,7 @@ public class ContinueProtocolHandler implements ProtocolHandler
             Request request = response.getRequest();
             HttpConversation conversation = ((HttpRequest)request).getConversation();
             // Mark the 100 Continue response as handled
-            conversation.setAttribute(ATTRIBUTE, Boolean.TRUE);
+            request.attribute(ATTRIBUTE, Boolean.TRUE);
 
             // Reset the conversation listeners, since we are going to receive another response code
             conversation.updateResponseListeners(null);

tests/test-http-client-transport/src/test/java/org/eclipse/jetty/http/client/HttpClientContinueTest.java

@@ -657,18 +657,7 @@ public class HttpClientContinueTest extends AbstractTest
             try (Socket socket = server.accept())
             {
                 // Read the request headers.
-                InputStream input = socket.getInputStream();
-                int crlfs = 0;
-                while (true)
-                {
-                    int read = input.read();
-                    if (read == '\r' || read == '\n')
-                        ++crlfs;
-                    else
-                        crlfs = 0;
-                    if (crlfs == 4)
-                        break;
-                }
+                readRequestHeaders(socket.getInputStream());
 
                 OutputStream output = socket.getOutputStream();
                 String responses = "" +
@@ -723,4 +712,74 @@ public class HttpClientContinueTest extends AbstractTest
         Assert.assertEquals(HttpStatus.OK_200, response.getStatus());
         Assert.assertArrayEquals(bytes, response.getContent());
     }
+
+    @Test
+    public void test_NoExpect_100Continue_ThenRedirect_Then100Continue_ThenResponse() throws Exception
+    {
+        Assume.assumeThat(transport, Matchers.is(Transport.HTTP));
+
+        startClient();
+        client.setMaxConnectionsPerDestination(1);
+
+        try (ServerSocket server = new ServerSocket())
+        {
+            server.bind(new InetSocketAddress("localhost", 0));
+
+            // No Expect header, no content.
+            CountDownLatch latch = new CountDownLatch(1);
+            client.newRequest("localhost", server.getLocalPort())
+                    .send(result ->
+                    {
+                        if (result.isSucceeded() && result.getResponse().getStatus() == HttpStatus.OK_200)
+                            latch.countDown();
+                    });
+
+            try (Socket socket = server.accept())
+            {
+                InputStream input = socket.getInputStream();
+                OutputStream output = socket.getOutputStream();
+
+                readRequestHeaders(input);
+                String response1 = "" +
+                        "HTTP/1.1 100 Continue\r\n" +
+                        "\r\n" +
+                        "HTTP/1.1 303 See Other\r\n" +
+                        "Location: /redirect\r\n" +
+                        "Content-Length: 0\r\n" +
+                        "\r\n";
+                output.write(response1.getBytes(StandardCharsets.UTF_8));
+                output.flush();
+
+                readRequestHeaders(input);
+                String response2 = "" +
+                        "HTTP/1.1 100 Continue\r\n" +
+                        "\r\n" +
+                        "HTTP/1.1 200 OK\r\n" +
+                        "Content-Length: 0\r\n" +
+                        "Connection: close\r\n" +
+                        "\r\n";
+                output.write(response2.getBytes(StandardCharsets.UTF_8));
+                output.flush();
+            }
+
+            Assert.assertTrue(latch.await(5, TimeUnit.SECONDS));
+        }
+    }
+
+    private void readRequestHeaders(InputStream input) throws IOException
+    {
+        int crlfs = 0;
+        while (true)
+        {
+            int read = input.read();
+            if (read < 0)
+                break;
+            if (read == '\r' || read == '\n')
+                ++crlfs;
+            else
+                crlfs = 0;
+            if (crlfs == 4)
+                break;
+        }
+    }
 }