1 files changed, 8 insertions, 2 deletions
diff --git a/src/network/access/qnetworkrequest.cpp b/src/network/access/qnetworkrequest.cpp
index b761af5..162392d 100644
--- a/src/network/access/qnetworkrequest.cpp
+++ b/src/network/access/qnetworkrequest.cpp
@@ -899,10 +899,16 @@ void QNetworkHeadersPrivate::parseAndSetHeader(const QByteArray &key, const QByt
     // is it a known header?
     QNetworkRequest::KnownHeaders parsedKey = parseHeaderName(key);
     if (parsedKey != QNetworkRequest::KnownHeaders(-1)) {
-        if (value.isNull())
+        if (value.isNull()) {
             cookedHeaders.remove(parsedKey);
-        else
+        } else if (parsedKey == QNetworkRequest::ContentLengthHeader
+                 && cookedHeaders.contains(QNetworkRequest::ContentLengthHeader)) {
+            // Only set the cooked header "Content-Length" once.
+            // See bug QTBUG-15311
+        } else {
             cookedHeaders.insert(parsedKey, parseHeaderValue(parsedKey, value));
+        }
+
     }
 }