fix bodyLengthMissmatch error handling

Author: dnadoba

Diff for: Sources/AsyncHTTPClient/ConnectionPool/HTTPRequestStateMachine.swift

@@ -198,14 +198,14 @@ struct HTTPRequestStateMachine {
             self.state = .failed(error)
             return .failRequest(error, .none)
 
-        case .running(.streaming, .waitingForHead),
+        case .running(.streaming, .waitingForHead) where error as? NIOSSLError == .uncleanShutdown,
              .running(.endSent, .waitingForHead) where error as? NIOSSLError == .uncleanShutdown:
             // if we received a NIOSSL.uncleanShutdown before we got an answer we should handle
             // this like a normal connection close. We will receive a call to channelInactive after
             // this error.
             return .wait
 
-        case .running(.streaming, .receivingBody(let responseHead, _)),
+        case .running(.streaming, .receivingBody(let responseHead, _)) where error as? NIOSSLError == .uncleanShutdown,
              .running(.endSent, .receivingBody(let responseHead, _)) where error as? NIOSSLError == .uncleanShutdown:
             // This code is only reachable for request and responses, which we expect to have a body.
             // We depend on logic from the HTTPResponseDecoder here. The decoder will emit an
@@ -270,7 +270,7 @@ struct HTTPRequestStateMachine {
 
             if let expected = expectedBodyLength, sentBodyBytes + part.readableBytes > expected {
                 let error = HTTPClientError.bodyLengthMismatch
-
+                self.state = .failed(error)
                 return .failRequest(error, .close)
             }
 

Diff for: Tests/AsyncHTTPClientTests/HTTPRequestStateMachineTests.swift

@@ -82,6 +82,9 @@ class HTTPRequestStateMachineTests: XCTestCase {
         }
 
         XCTAssertEqual(error as? HTTPClientError, .bodyLengthMismatch)
+        
+        // if another error happens the new one is ignored
+        XCTAssertEqual(state.errorHappened(HTTPClientError.remoteConnectionClosed), .wait)
     }
 
     func testPOSTContentLengthIsTooShort() {
@@ -521,6 +524,28 @@ class HTTPRequestStateMachineTests: XCTestCase {
         XCTAssertEqual(state.channelRead(.end(nil)), .wait)
         XCTAssertEqual(state.channelInactive(), .wait)
     }
+    
+    func testNIOSSLErrorUncleanShutdownShouldBeTreatedAsRemoteConnectionCloseWhileInWaitingForHeadState() {
+        var state = HTTPRequestStateMachine(isChannelWritable: true)
+        let requestHead = HTTPRequestHead(version: .http1_1, method: .GET, uri: "/")
+        let metadata = RequestFramingMetadata(connectionClose: false, body: .fixedSize(0))
+        XCTAssertEqual(state.startRequest(head: requestHead, metadata: metadata), .sendRequestHead(requestHead, startBody: false))
+
+        XCTAssertEqual(state.errorHappened(NIOSSLError.uncleanShutdown), .wait)
+        XCTAssertEqual(state.channelInactive(), .failRequest(HTTPClientError.remoteConnectionClosed, .none))
+    }
+    
+    
+    func testArbitraryErrorShouldBeTreatedAsARequestFailureWhileInWaitingForHeadState() {
+        struct ArbitraryError: Error {}
+        var state = HTTPRequestStateMachine(isChannelWritable: true)
+        let requestHead = HTTPRequestHead(version: .http1_1, method: .GET, uri: "/")
+        let metadata = RequestFramingMetadata(connectionClose: false, body: .fixedSize(0))
+        XCTAssertEqual(state.startRequest(head: requestHead, metadata: metadata), .sendRequestHead(requestHead, startBody: false))
+
+        XCTAssertEqual(state.errorHappened(ArbitraryError()), .failRequest(ArbitraryError(), .close))
+        XCTAssertEqual(state.channelInactive(), .wait)
+    }
 
     func testFailHTTP1RequestWithContentLengthWithNIOSSLErrorUncleanShutdownButIgnoreIt() {
         var state = HTTPRequestStateMachine(isChannelWritable: true)