Read the response even if writing the request fails

Closes: 1001

mockwebserver/src/main/kotlin/okhttp3/mockwebserver/MockResponse.kt

@@ -60,7 +60,8 @@ class MockResponse : Cloneable {
   /**
    * Sets the [HTTP/2 error code](https://tools.ietf.org/html/rfc7540#section-7) to be
    * returned when resetting the stream.
-   * This is only valid with [SocketPolicy.RESET_STREAM_AT_START].
+   * This is only valid with [SocketPolicy.RESET_STREAM_AT_START] and
+   * [SocketPolicy.DO_NOT_READ_REQUEST_BODY].
    */
   @set:JvmName("http2ErrorCode")
   var http2ErrorCode = -1

mockwebserver/src/main/kotlin/okhttp3/mockwebserver/MockWebServer.kt

@@ -72,6 +72,7 @@ import okhttp3.mockwebserver.SocketPolicy.DISCONNECT_AT_END
 import okhttp3.mockwebserver.SocketPolicy.DISCONNECT_AT_START
 import okhttp3.mockwebserver.SocketPolicy.DISCONNECT_DURING_REQUEST_BODY
 import okhttp3.mockwebserver.SocketPolicy.DISCONNECT_DURING_RESPONSE_BODY
+import okhttp3.mockwebserver.SocketPolicy.DO_NOT_READ_REQUEST_BODY
 import okhttp3.mockwebserver.SocketPolicy.EXPECT_CONTINUE
 import okhttp3.mockwebserver.SocketPolicy.FAIL_HANDSHAKE
 import okhttp3.mockwebserver.SocketPolicy.NO_RESPONSE
@@ -627,7 +628,7 @@ class MockWebServer : ExternalResource(), Closeable {
 
       // See warnings associated with these socket policies in SocketPolicy.
       when (response.socketPolicy) {
-        DISCONNECT_AT_END -> {
+        DISCONNECT_AT_END, DO_NOT_READ_REQUEST_BODY -> {
           socket.close()
           return false
         }
@@ -719,7 +720,9 @@ class MockWebServer : ExternalResource(), Closeable {
 
       var hasBody = false
       val policy = dispatcher.peek()
-      if (contentLength != -1L) {
+      if (policy.socketPolicy == DO_NOT_READ_REQUEST_BODY) {
+        // Ignore the body completely.
+      } else if (contentLength != -1L) {
         hasBody = contentLength > 0L
         throttledTransfer(policy, socket, source, requestBody.buffer(), contentLength, true)
       } else if (chunked) {
@@ -966,7 +969,8 @@ class MockWebServer : ExternalResource(), Closeable {
 
       val response: MockResponse = dispatcher.dispatch(request)
 
-      if (response.socketPolicy === DISCONNECT_AFTER_REQUEST) {
+      val socketPolicy = response.socketPolicy
+      if (socketPolicy === DISCONNECT_AFTER_REQUEST) {
         socket.close()
         return
       }
@@ -977,9 +981,15 @@ class MockWebServer : ExternalResource(), Closeable {
                 "and responded: $response protocol is $protocol")
       }
 
-      if (response.socketPolicy === DISCONNECT_AT_END) {
-        val connection = stream.connection
-        connection.shutdown(ErrorCode.NO_ERROR)
+      when (socketPolicy) {
+        DISCONNECT_AT_END -> {
+          stream.connection.shutdown(ErrorCode.NO_ERROR)
+        }
+        DO_NOT_READ_REQUEST_BODY -> {
+          stream.close(ErrorCode.fromHttp2(response.http2ErrorCode)!!, null)
+        }
+        else -> {
+        }
       }
     }
 
@@ -1019,7 +1029,7 @@ class MockWebServer : ExternalResource(), Closeable {
       val body = Buffer()
       val requestLine = "$method $path HTTP/1.1"
       var exception: IOException? = null
-      if (readBody && !peek.isDuplex) {
+      if (readBody && !peek.isDuplex && peek.socketPolicy !== DO_NOT_READ_REQUEST_BODY) {
         try {
           val contentLengthString = headers["content-length"]
           val byteCount = contentLengthString?.toLong() ?: Long.MAX_VALUE

mockwebserver/src/main/kotlin/okhttp3/mockwebserver/SocketPolicy.kt

@@ -75,6 +75,13 @@ enum class SocketPolicy {
   /** Close connection after writing half of the response body (if present). */
   DISCONNECT_DURING_RESPONSE_BODY,
 
+  /**
+   * Process the response without even attempting to reading the request body. For HTTP/2 this will
+   * send [MockResponse.getHttp2ErrorCode] after the response body or trailers. For HTTP/1 this will
+   * close the socket after the response body or trailers.
+   */
+  DO_NOT_READ_REQUEST_BODY,
+
   /** Don't trust the client during the SSL handshake. */
   FAIL_HANDSHAKE,
 

okhttp/src/main/kotlin/okhttp3/internal/connection/Exchange.kt

@@ -43,10 +43,14 @@ class Exchange(
   internal val finder: ExchangeFinder,
   private val codec: ExchangeCodec
 ) {
-  /** Returns true if the request body need not complete before the response body starts. */
+  /** True if the request body need not complete before the response body starts. */
   internal var isDuplex: Boolean = false
     private set
 
+  /** True if there was an exception on the connection to the peer. */
+  internal var hasFailure: Boolean = false
+    private set
+
   internal val connection: RealConnection = codec.connection
 
   internal val isCoalescedConnection: Boolean
@@ -163,6 +167,7 @@ class Exchange(
   }
 
   private fun trackFailure(e: IOException) {
+    hasFailure = true
     finder.trackFailure(e)
     codec.connection.trackFailure(call, e)
   }

okhttp/src/main/kotlin/okhttp3/internal/http/CallServerInterceptor.kt

@@ -20,6 +20,7 @@ import java.net.ProtocolException
 import okhttp3.Interceptor
 import okhttp3.Response
 import okhttp3.internal.EMPTY_RESPONSE
+import okhttp3.internal.http2.ConnectionShutdownException
 import okio.buffer
 
 /** This is the last interceptor in the chain. It makes a network call to the server. */
@@ -33,98 +34,118 @@ class CallServerInterceptor(private val forWebSocket: Boolean) : Interceptor {
     val requestBody = request.body
     val sentRequestMillis = System.currentTimeMillis()
 
-    exchange.writeRequestHeaders(request)
-
     var invokeStartEvent = true
     var responseBuilder: Response.Builder? = null
-    if (HttpMethod.permitsRequestBody(request.method) && requestBody != null) {
-      // If there's a "Expect: 100-continue" header on the request, wait for a "HTTP/1.1 100
-      // Continue" response before transmitting the request body. If we don't get that, return
-      // what we did get (such as a 4xx response) without ever transmitting the request body.
-      if ("100-continue".equals(request.header("Expect"), ignoreCase = true)) {
-        exchange.flushRequest()
-        responseBuilder = exchange.readResponseHeaders(expectContinue = true)
-        exchange.responseHeadersStart()
-        invokeStartEvent = false
-      }
-      if (responseBuilder == null) {
-        if (requestBody.isDuplex()) {
-          // Prepare a duplex body so that the application can send a request body later.
+    var sendRequestException: IOException? = null
+    try {
+      exchange.writeRequestHeaders(request)
+
+      if (HttpMethod.permitsRequestBody(request.method) && requestBody != null) {
+        // If there's a "Expect: 100-continue" header on the request, wait for a "HTTP/1.1 100
+        // Continue" response before transmitting the request body. If we don't get that, return
+        // what we did get (such as a 4xx response) without ever transmitting the request body.
+        if ("100-continue".equals(request.header("Expect"), ignoreCase = true)) {
           exchange.flushRequest()
-          val bufferedRequestBody = exchange.createRequestBody(request, true).buffer()
-          requestBody.writeTo(bufferedRequestBody)
+          responseBuilder = exchange.readResponseHeaders(expectContinue = true)
+          exchange.responseHeadersStart()
+          invokeStartEvent = false
+        }
+        if (responseBuilder == null) {
+          if (requestBody.isDuplex()) {
+            // Prepare a duplex body so that the application can send a request body later.
+            exchange.flushRequest()
+            val bufferedRequestBody = exchange.createRequestBody(request, true).buffer()
+            requestBody.writeTo(bufferedRequestBody)
+          } else {
+            // Write the request body if the "Expect: 100-continue" expectation was met.
+            val bufferedRequestBody = exchange.createRequestBody(request, false).buffer()
+            requestBody.writeTo(bufferedRequestBody)
+            bufferedRequestBody.close()
+          }
         } else {
-          // Write the request body if the "Expect: 100-continue" expectation was met.
-          val bufferedRequestBody = exchange.createRequestBody(request, false).buffer()
-          requestBody.writeTo(bufferedRequestBody)
-          bufferedRequestBody.close()
+          exchange.noRequestBody()
+          if (!exchange.connection.isMultiplexed) {
+            // If the "Expect: 100-continue" expectation wasn't met, prevent the HTTP/1 connection
+            // from being reused. Otherwise we're still obligated to transmit the request body to
+            // leave the connection in a consistent state.
+            exchange.noNewExchangesOnConnection()
+          }
         }
       } else {
         exchange.noRequestBody()
-        if (!exchange.connection.isMultiplexed) {
-          // If the "Expect: 100-continue" expectation wasn't met, prevent the HTTP/1 connection
-          // from being reused. Otherwise we're still obligated to transmit the request body to
-          // leave the connection in a consistent state.
-          exchange.noNewExchangesOnConnection()
-        }
       }
-    } else {
-      exchange.noRequestBody()
-    }
 
-    if (requestBody == null || !requestBody.isDuplex()) {
-      exchange.finishRequest()
-    }
-    if (responseBuilder == null) {
-      responseBuilder = exchange.readResponseHeaders(expectContinue = false)!!
-      if (invokeStartEvent) {
-        exchange.responseHeadersStart()
-        invokeStartEvent = false
+      if (requestBody == null || !requestBody.isDuplex()) {
+        exchange.finishRequest()
+      }
+    } catch (e: IOException) {
+      if (e is ConnectionShutdownException) {
+        throw e // No request was sent so there's no response to read.
+      }
+      if (!exchange.hasFailure) {
+        throw e // Don't attempt to read the response; we failed to send the request.
       }
+      sendRequestException = e
     }
-    var response = responseBuilder
-        .request(request)
-        .handshake(exchange.connection.handshake())
-        .sentRequestAtMillis(sentRequestMillis)
-        .receivedResponseAtMillis(System.currentTimeMillis())
-        .build()
-    var code = response.code
-    if (code == 100) {
-      // Server sent a 100-continue even though we did not request one. Try again to read the actual
-      // response status.
-      responseBuilder = exchange.readResponseHeaders(expectContinue = false)!!
-      if (invokeStartEvent) {
-        exchange.responseHeadersStart()
+
+    try {
+      if (responseBuilder == null) {
+        responseBuilder = exchange.readResponseHeaders(expectContinue = false)!!
+        if (invokeStartEvent) {
+          exchange.responseHeadersStart()
+          invokeStartEvent = false
+        }
       }
-      response = responseBuilder
+      var response = responseBuilder
           .request(request)
           .handshake(exchange.connection.handshake())
           .sentRequestAtMillis(sentRequestMillis)
           .receivedResponseAtMillis(System.currentTimeMillis())
           .build()
-      code = response.code
-    }
+      var code = response.code
+      if (code == 100) {
+        // Server sent a 100-continue even though we did not request one. Try again to read the
+        // actual response status.
+        responseBuilder = exchange.readResponseHeaders(expectContinue = false)!!
+        if (invokeStartEvent) {
+          exchange.responseHeadersStart()
+        }
+        response = responseBuilder
+            .request(request)
+            .handshake(exchange.connection.handshake())
+            .sentRequestAtMillis(sentRequestMillis)
+            .receivedResponseAtMillis(System.currentTimeMillis())
+            .build()
+        code = response.code
+      }
 
-    exchange.responseHeadersEnd(response)
+      exchange.responseHeadersEnd(response)
 
-    response = if (forWebSocket && code == 101) {
-      // Connection is upgrading, but we need to ensure interceptors see a non-null response body.
-      response.newBuilder()
-          .body(EMPTY_RESPONSE)
-          .build()
-    } else {
-      response.newBuilder()
-          .body(exchange.openResponseBody(response))
-          .build()
-    }
-    if ("close".equals(response.request.header("Connection"), ignoreCase = true) ||
-        "close".equals(response.header("Connection"), ignoreCase = true)) {
-      exchange.noNewExchangesOnConnection()
-    }
-    if ((code == 204 || code == 205) && response.body?.contentLength() ?: -1L > 0L) {
-      throw ProtocolException(
-          "HTTP $code had non-zero Content-Length: ${response.body?.contentLength()}")
+      response = if (forWebSocket && code == 101) {
+        // Connection is upgrading, but we need to ensure interceptors see a non-null response body.
+        response.newBuilder()
+            .body(EMPTY_RESPONSE)
+            .build()
+      } else {
+        response.newBuilder()
+            .body(exchange.openResponseBody(response))
+            .build()
+      }
+      if ("close".equals(response.request.header("Connection"), ignoreCase = true) ||
+          "close".equals(response.header("Connection"), ignoreCase = true)) {
+        exchange.noNewExchangesOnConnection()
+      }
+      if ((code == 204 || code == 205) && response.body?.contentLength() ?: -1L > 0L) {
+        throw ProtocolException(
+            "HTTP $code had non-zero Content-Length: ${response.body?.contentLength()}")
+      }
+      return response
+    } catch (e: IOException) {
+      if (sendRequestException != null) {
+        sendRequestException.addSuppressed(e)
+        throw sendRequestException
+      }
+      throw e
     }
-    return response
   }
 }

okhttp/src/main/kotlin/okhttp3/internal/http1/Http1ExchangeCodec.kt

@@ -170,7 +170,9 @@ class Http1ExchangeCodec(
   }
 
   override fun readResponseHeaders(expectContinue: Boolean): Response.Builder? {
-    check(state == STATE_OPEN_REQUEST_BODY || state == STATE_READ_RESPONSE_HEADERS) {
+    check(state == STATE_OPEN_REQUEST_BODY ||
+        state == STATE_WRITING_REQUEST_BODY ||
+        state == STATE_READ_RESPONSE_HEADERS) {
       "state: $state"
     }
 

okhttp/src/main/kotlin/okhttp3/internal/http2/Http2ExchangeCodec.kt

@@ -93,7 +93,8 @@ class Http2ExchangeCodec(
   }
 
   override fun readResponseHeaders(expectContinue: Boolean): Response.Builder? {
-    val headers = stream!!.takeHeaders()
+    val stream = stream ?: throw IOException("stream wasn't created")
+    val headers = stream.takeHeaders()
     val responseBuilder = readHttp2HeadersList(headers, protocol)
     return if (expectContinue && responseBuilder.code == HTTP_CONTINUE) {
       null

okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Stream.kt

@@ -350,7 +350,7 @@ class Http2Stream internal constructor(
         synchronized(this@Http2Stream) {
           readTimeout.enter()
           try {
-            if (errorCode != null) {
+            if (errorCode != null && !finished) {
               // Prepare to deliver an error.
               errorExceptionToDeliver = errorException ?: StreamResetException(errorCode!!)
             }

okhttp/src/test/java/okhttp3/EventListenerTest.java

@@ -1118,7 +1118,7 @@ private void writeChunk(BufferedSink sink) throws IOException {
     assertThat(listener.recordedEventTypes()).containsExactly(
         "CallStart", "ProxySelectStart", "ProxySelectEnd", "DnsStart", "DnsEnd", "ConnectStart",
         "ConnectEnd", "ConnectionAcquired", "RequestHeadersStart", "RequestHeadersEnd",
-        "RequestBodyStart", "RequestFailed", "ConnectionReleased", "CallFailed");
+        "RequestBodyStart", "RequestFailed", "ResponseFailed", "ConnectionReleased", "CallFailed");
   }
 
   @Test public void requestBodySuccessHttp1OverHttps() throws IOException {