Switch from binary JSON to JSON for QWebChannel messages

Qt's binary JSON has been deprecated in favor of CBOR. However, since
we have to convert to/from JSON anyway in order to pass messages
to/from Chromium, there's not much point to use a binary intermediate
format in the first place. So, let's just use JSON.

Fixes: QTBUG-85688
Change-Id: I9c3e4608bee38d460eaf87843c339d5037ed9888
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

2 files changed, 10 insertions, 21 deletions

diff --git a/src/core/renderer/web_channel_ipc_transport.cpp b/src/core/renderer/web_channel_ipc_transport.cpp
index 1fb3bc678..496417329 100644
--- a/src/core/renderer/web_channel_ipc_transport.cpp
+++ b/src/core/renderer/web_channel_ipc_transport.cpp
@@ -152,22 +152,13 @@ void WebChannelTransport::NativeQtSendMessage(gin::Arguments *args)
         return;
     }
     v8::Local<v8::String> jsonString = v8::Local<v8::String>::Cast(jsonValue);
+    std::vector<uint8_t> json(jsonString->Utf8Length(isolate), 0);
+    jsonString->WriteUtf8(isolate, reinterpret_cast<char *>(json.data()), json.size(), nullptr,
+                          v8::String::REPLACE_INVALID_UTF8);
 
-    QByteArray json(jsonString->Utf8Length(isolate), 0);
-    jsonString->WriteUtf8(isolate, json.data(), json.size(), nullptr, v8::String::REPLACE_INVALID_UTF8);
-
-    QJsonParseError error;
-    QJsonDocument doc = QJsonDocument::fromJson(json, &error);
-    if (error.error != QJsonParseError::NoError) {
-        args->ThrowTypeError("Invalid JSON");
-        return;
-    }
-
-    int size = 0;
-    const char *rawData = doc.rawData(&size);
     mojo::AssociatedRemote<qtwebchannel::mojom::WebChannelTransportHost> webChannelTransport;
     renderFrame->GetRemoteAssociatedInterfaces()->GetInterface(&webChannelTransport);
-    webChannelTransport->DispatchWebChannelMessage(std::vector<uint8_t>(rawData, rawData + size));
+    webChannelTransport->DispatchWebChannelMessage(json);
 }
 
 gin::ObjectTemplateBuilder WebChannelTransport::GetObjectTemplateBuilder(v8::Isolate *isolate)
@@ -213,18 +204,14 @@ void WebChannelIPCTransport::ResetWorldId()
     m_worldId = 0;
 }
 
-void WebChannelIPCTransport::DispatchWebChannelMessage(const std::vector<uint8_t> &binaryJson, uint32_t worldId)
+void WebChannelIPCTransport::DispatchWebChannelMessage(const std::vector<uint8_t> &json,
+                                                       uint32_t worldId)
 {
     DCHECK(m_worldId == worldId);
 
     if (!m_canUseContext)
         return;
 
-    QJsonDocument doc = QJsonDocument::fromRawData(reinterpret_cast<const char *>(binaryJson.data()), binaryJson.size(),
-                                                   QJsonDocument::BypassValidation);
-    DCHECK(doc.isObject());
-    QByteArray json = doc.toJson(QJsonDocument::Compact);
-
     blink::WebLocalFrame *frame = render_frame()->GetWebFrame();
     v8::Isolate *isolate = blink::MainThreadIsolate();
     v8::HandleScope handleScope(isolate);
@@ -255,7 +242,9 @@ void WebChannelIPCTransport::DispatchWebChannelMessage(const std::vector<uint8_t
     v8::Local<v8::Object> messageObject(v8::Object::New(isolate));
     v8::Maybe<bool> wasSet = messageObject->DefineOwnProperty(
             context, v8::String::NewFromUtf8(isolate, "data").ToLocalChecked(),
-            v8::String::NewFromUtf8(isolate, json.constData(), v8::NewStringType::kNormal, json.size()).ToLocalChecked(),
+            v8::String::NewFromUtf8(isolate, reinterpret_cast<const char *>(json.data()),
+                                    v8::NewStringType::kNormal, json.size())
+                    .ToLocalChecked(),
             v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
     DCHECK(!wasSet.IsNothing() && wasSet.FromJust());
 
diff --git a/src/core/renderer/web_channel_ipc_transport.h b/src/core/renderer/web_channel_ipc_transport.h
index 15778a7bc..7c3b21eec 100644
--- a/src/core/renderer/web_channel_ipc_transport.h
+++ b/src/core/renderer/web_channel_ipc_transport.h
@@ -61,7 +61,7 @@ private:
     // qtwebchannel::mojom::WebChannelTransportRender
     void SetWorldId(uint32_t worldId) override;
     void ResetWorldId() override;
-    void DispatchWebChannelMessage(const std::vector<uint8_t> &binaryJson, uint32_t worldId) override;
+    void DispatchWebChannelMessage(const std::vector<uint8_t> &json, uint32_t worldId) override;
 
     // RenderFrameObserver
     void WillReleaseScriptContext(v8::Local<v8::Context> context, int worldId) override;