From: ckamm <mail@ckamm.de>
Date: Thu, 20 Apr 2017 07:21:33 +0000 (+0200)
Subject: Fix a crash in ProxyAuthHandler (#5711)
X-Git-Tag: archive/raspbian/3.16.7-1_deb13u1+rpi1~1^2~722^2~33
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=543e8a224c951516552dcb8377c21fa75c2380f8;p=nextcloud-desktop.git

Fix a crash in ProxyAuthHandler (#5711)

See
https://sentry.io/owncloud/desktop-win-and-mac/issues/243433178/activity/
https://sentry.io/owncloud/desktop-win-and-mac/issues/234182688/activity/

The problem was that an account's QNetworkAccessManager can be deleted
when reentering the event loop.
---

diff --git a/src/gui/proxyauthhandler.cpp b/src/gui/proxyauthhandler.cpp
index a3f0fba7e..e80b540e8 100644
--- a/src/gui/proxyauthhandler.cpp
+++ b/src/gui/proxyauthhandler.cpp
@@ -81,9 +81,14 @@ void ProxyAuthHandler::handleProxyAuthenticationRequired(
     }
 
     // Find the responsible QNAM if possible.
-    QNetworkAccessManager* sending_qnam = qobject_cast<QNetworkAccessManager*>(sender());
+    QNetworkAccessManager* sending_qnam = 0;
+    QWeakPointer<QNetworkAccessManager> qnam_alive;
     if (Account* account = qobject_cast<Account*>(sender())) {
-        sending_qnam = account->networkAccessManager();
+        // Since we go into an event loop, it's possible for the account's qnam
+        // to be destroyed before we get back. We can use this to check for its
+        // liveness.
+        qnam_alive = account->sharedNetworkAccessManager();
+        sending_qnam = qnam_alive.data();
     }
     if (!sending_qnam) {
         qDebug() << "Could not get the sending QNAM for" << sender();
@@ -122,6 +127,7 @@ void ProxyAuthHandler::handleProxyAuthenticationRequired(
     qDebug() << "got creds for" << _proxy;
     authenticator->setUser(_username);
     authenticator->setPassword(_password);
+    sending_qnam = qnam_alive.data();
     if (sending_qnam) {
         _gaveCredentialsTo.insert(sending_qnam);
         connect(sending_qnam, SIGNAL(destroyed(QObject*)),
diff --git a/src/libsync/account.cpp b/src/libsync/account.cpp
index b92609459..34f0f374a 100644
--- a/src/libsync/account.cpp
+++ b/src/libsync/account.cpp
@@ -202,6 +202,11 @@ QNetworkAccessManager *Account::networkAccessManager()
     return _am.data();
 }
 
+QSharedPointer<QNetworkAccessManager> Account::sharedNetworkAccessManager()
+{
+    return _am;
+}
+
 QNetworkReply *Account::sendRequest(const QByteArray &verb, const QUrl &url, QNetworkRequest req, QIODevice *data)
 {
     req.setUrl(url);
diff --git a/src/libsync/account.h b/src/libsync/account.h
index 0f55c5a1d..1369b5df2 100644
--- a/src/libsync/account.h
+++ b/src/libsync/account.h
@@ -185,6 +185,7 @@ public:
 
     void resetNetworkAccessManager();
     QNetworkAccessManager* networkAccessManager();
+    QSharedPointer<QNetworkAccessManager> sharedNetworkAccessManager();
 
     /// Called by network jobs on credential errors, emits invalidCredentials()
     void handleInvalidCredentials();