From 536cab1a93850c80e18f44872ecca7decdeb7eea Mon Sep 17 00:00:00 2001
From: Lorn Potter <lorn.potter@gmail.com>
Date: Mon, 29 Jul 2019 10:07:31 +1000
Subject: [PATCH] wasm: add network object checking

This should help when things are moving fast, and downloads and
network object are destroyed before the callbacks finishes.

Change-Id: I1f65965bd61efc2e641d03eb071f23e684dd5c44
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
---
 src/network/access/qnetworkreplywasmimpl.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/network/access/qnetworkreplywasmimpl.cpp b/src/network/access/qnetworkreplywasmimpl.cpp
index 53784407d88..f28b8415d13 100644
--- a/src/network/access/qnetworkreplywasmimpl.cpp
+++ b/src/network/access/qnetworkreplywasmimpl.cpp
@@ -63,6 +63,8 @@ static void q_requestErrorCallback(val event)
         return;
 
     val xhr = event["target"];
+    if (xhr.isNull() || xhr.isUndefined())
+        return;
 
     quintptr func = xhr["data-handler"].as<quintptr>();
     QNetworkReplyWasmImplPrivate *reply = reinterpret_cast<QNetworkReplyWasmImplPrivate*>(func);
@@ -84,6 +86,8 @@ static void q_progressCallback(val event)
         return;
 
     val xhr = event["target"];
+    if (xhr.isNull() || xhr.isUndefined())
+        return;
 
     QNetworkReplyWasmImplPrivate *reply =
             reinterpret_cast<QNetworkReplyWasmImplPrivate*>(xhr["data-handler"].as<quintptr>());
@@ -99,6 +103,8 @@ static void q_loadCallback(val event)
         return;
 
     val xhr = event["target"];
+    if (xhr.isNull() || xhr.isUndefined())
+        return;
 
     QNetworkReplyWasmImplPrivate *reply =
             reinterpret_cast<QNetworkReplyWasmImplPrivate*>(xhr["data-handler"].as<quintptr>());
@@ -123,8 +129,13 @@ static void q_loadCallback(val event)
         } else if (responseType == "arraybuffer" || responseType == "blob") {
             // handle this data in the FileReader, triggered by the call to readAsArrayBuffer
             val blob = xhr["response"];
+            if (blob.isNull() || blob.isUndefined())
+                return;
 
             val reader = val::global("FileReader").new_();
+            if (reader.isNull() || reader.isUndefined())
+                return;
+
             reader.set("onload", val::module_property("qt_QNetworkReplyWasmImplPrivate_readBinary"));
             reader.set("data-handler", xhr["data-handler"]);
 
@@ -151,6 +162,8 @@ static void q_responseHeadersCallback(val event)
         return;
 
     val xhr = event["target"];
+    if (xhr.isNull() || xhr.isUndefined())
+        return;
 
     if (xhr["readyState"].as<int>() == 2) { // HEADERS_RECEIVED
         std::string responseHeaders = xhr.call<std::string>("getAllResponseHeaders");
@@ -170,6 +183,8 @@ static void q_readBinary(val event)
         return;
 
     val fileReader = event["target"];
+    if (fileReader.isNull() || fileReader.isUndefined())
+        return;
 
     QNetworkReplyWasmImplPrivate *reply =
             reinterpret_cast<QNetworkReplyWasmImplPrivate*>(fileReader["data-handler"].as<quintptr>());
@@ -180,6 +195,9 @@ static void q_readBinary(val event)
 
     // Set up source typed array
     val result = fileReader["result"]; // ArrayBuffer
+    if (result.isNull() || result.isUndefined())
+        return;
+
     val Uint8Array = val::global("Uint8Array");
     val sourceTypedArray = Uint8Array.new_(result);