Improve thread safety and behavior of custom URL requests

Adds thread protection between the UI and IO threads access to the
QIODevice, and changes it to a QPointer, so we can tell if the user
deletes it.

Change-Id: I3e7b3f682d4c5a145d75cd5822affcfc9012cff7
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/webenginewidgets/api/qwebengineprofile.cpp b/src/webenginewidgets/api/qwebengineprofile.cpp
index e63519d2c..adccfca2a 100644
--- a/src/webenginewidgets/api/qwebengineprofile.cpp
+++ b/src/webenginewidgets/api/qwebengineprofile.cpp
@@ -494,6 +494,10 @@ void QWebEngineProfilePrivate::installUrlSchemeHandler(QWebEngineUrlSchemeHandle
         return;
     }
 
+    if (m_urlSchemeHandlers.contains(scheme)) {
+        qWarning() << "URL scheme handler already installed for the scheme: " << scheme;
+        return;
+    }
     m_urlSchemeHandlers.insert(scheme, handler);
     browserContext()->customUrlSchemeHandlers().append(handler->d_func());
     browserContext()->updateCustomUrlSchemeHandlers();