QNAM HTTP: Fix bug with explicitly zero-length compressed responses.

In the case of a response with e.g content-encoding "gzip" and
content-length "0", the HTTP backend would incorrectly fall back to
the "unspecified length" code path and wait for readyRead() forever.

Task-number: QTBUG-18232
Reviewed-by: Markus Goetz

2 files changed, 28 insertions, 1 deletions

diff --git a/src/network/access/qhttpnetworkreply.cpp b/src/network/access/qhttpnetworkreply.cpp
index e608005..d329c10 100644
--- a/src/network/access/qhttpnetworkreply.cpp
+++ b/src/network/access/qhttpnetworkreply.cpp
@@ -811,8 +811,14 @@ bool QHttpNetworkReplyPrivate::expectContent()
         return false;
     if (request.operation() == QHttpNetworkRequest::Head)
         return !shouldEmitSignals();
-    if (contentLength() == 0)
+    qint64 expectedContentLength = contentLength();
+    if (expectedContentLength == 0)
         return false;
+    if (expectedContentLength == -1 && bodyLength == 0) {
+        // The content-length header was stripped, but its value was 0.
+        // This would be the case for an explicitly zero-length compressed response.
+        return false;
+    }
     return true;
 }
 
diff --git a/tests/auto/qnetworkreply/tst_qnetworkreply.cpp b/tests/auto/qnetworkreply/tst_qnetworkreply.cpp
index 81278b6..d9285c8 100644
--- a/tests/auto/qnetworkreply/tst_qnetworkreply.cpp
+++ b/tests/auto/qnetworkreply/tst_qnetworkreply.cpp
@@ -329,6 +329,8 @@ private Q_SLOTS:
 
     void qtbug15311doubleContentLength();
 
+    void qtbug18232gzipContentLengthZero();
+
     void synchronousRequest_data();
     void synchronousRequest();
     void synchronousRequestSslFailure();
@@ -5217,6 +5219,25 @@ void tst_QNetworkReply::qtbug15311doubleContentLength()
     QCOMPARE(reply->readAll(), QByteArray("ABC"));
 }
 
+void tst_QNetworkReply::qtbug18232gzipContentLengthZero()
+{
+    QByteArray response("HTTP/1.0 200 OK\r\nContent-Encoding: gzip\r\nContent-Length: 0\r\n\r\n");
+    MiniHttpServer server(response);
+    server.doClose = true;
+
+    QNetworkRequest request(QUrl("http://localhost:" + QString::number(server.serverPort())));
+    QNetworkReplyPtr reply = manager.get(request);
+
+    connect(reply, SIGNAL(finished()), &QTestEventLoop::instance(), SLOT(exitLoop()));
+    QTestEventLoop::instance().enterLoop(10);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+    QVERIFY(reply->isFinished());
+    QCOMPARE(reply->error(), QNetworkReply::NoError);
+    QCOMPARE(reply->size(), qint64(0));
+    QCOMPARE(reply->header(QNetworkRequest::ContentLengthHeader).toLongLong(), qint64(0));
+    QCOMPARE(reply->readAll(), QByteArray());
+}
+
 void tst_QNetworkReply::synchronousRequest_data()
 {
     QTest::addColumn<QUrl>("url");