From ac179d0f701df2d92bc67fd6971e75fb3d2454d5 Mon Sep 17 00:00:00 2001
From: Michael Zanetti <michael_zanetti@gmx.net>
Date: Thu, 6 Jul 2017 17:05:28 +0200
Subject: [PATCH] fix avahi service browser destruction

without keeping track of the avahi service resolvers and
destroying them when the parent object goes away, callbacks
might be called after after the dhe destruction and passing
an invalid userdata pointer.
---
 .../network/avahi/qtavahiservicebrowser_p.cpp | 19 +++++++++++++++----
 .../network/avahi/qtavahiservicebrowser_p.h   |  2 ++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/libguh/network/avahi/qtavahiservicebrowser_p.cpp b/libguh/network/avahi/qtavahiservicebrowser_p.cpp
index 4bb6eee2..e23f3bce 100644
--- a/libguh/network/avahi/qtavahiservicebrowser_p.cpp
+++ b/libguh/network/avahi/qtavahiservicebrowser_p.cpp
@@ -35,6 +35,13 @@ QtAvahiServiceBrowserPrivate::QtAvahiServiceBrowserPrivate(QtAvahiClient *client
 
 }
 
+QtAvahiServiceBrowserPrivate::~QtAvahiServiceBrowserPrivate()
+{
+    foreach (AvahiServiceResolver *resolver, m_serviceResolvers) {
+        avahi_service_resolver_free(resolver);
+    }
+}
+
 void QtAvahiServiceBrowserPrivate::callbackServiceTypeBrowser(AvahiServiceTypeBrowser *browser, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, const char *type, const char *domain, AvahiLookupResultFlags flags, void *userdata)
 {
     Q_UNUSED(browser)
@@ -79,9 +86,9 @@ void QtAvahiServiceBrowserPrivate::callbackServiceBrowser(AvahiServiceBrowser *b
         return;
 
     switch (event) {
-    case AVAHI_BROWSER_NEW:
+    case AVAHI_BROWSER_NEW: {
         // Start resolving new service
-        if (!(avahi_service_resolver_new(serviceBrowser->d_ptr->client->client,
+        AvahiServiceResolver *resolver = avahi_service_resolver_new(serviceBrowser->d_ptr->client->client,
                                          interface,
                                          protocol,
                                          name,
@@ -90,11 +97,14 @@ void QtAvahiServiceBrowserPrivate::callbackServiceBrowser(AvahiServiceBrowser *b
                                          AVAHI_PROTO_UNSPEC,
                                          (AvahiLookupFlags) 0,
                                          QtAvahiServiceBrowserPrivate::callbackServiceResolver,
-                                         serviceBrowser))) {
-
+                                         serviceBrowser);
+        if (resolver) {
+            serviceBrowser->d_ptr->m_serviceResolvers.append(resolver);
+        } else {
             qCWarning(dcAvahi()) << "Failed to resolve service" << QString(name) << ":" << avahi_strerror(avahi_client_errno(serviceBrowser->d_ptr->client->client));
         }
         break;
+    }
     case AVAHI_BROWSER_REMOVE: {
         // Remove the service
         foreach (const AvahiServiceEntry &entry, serviceBrowser->m_serviceEntries) {
@@ -166,6 +176,7 @@ void QtAvahiServiceBrowserPrivate::callbackServiceResolver(AvahiServiceResolver
         emit serviceBrowser->serviceEntryAdded(entry);
     }
     }
+    serviceBrowser->d_ptr->m_serviceResolvers.removeAll(resolver);
     avahi_service_resolver_free(resolver);
 
 }
diff --git a/libguh/network/avahi/qtavahiservicebrowser_p.h b/libguh/network/avahi/qtavahiservicebrowser_p.h
index 393c80e0..1ef3a9e0 100644
--- a/libguh/network/avahi/qtavahiservicebrowser_p.h
+++ b/libguh/network/avahi/qtavahiservicebrowser_p.h
@@ -35,6 +35,7 @@ class LIBGUH_EXPORT QtAvahiServiceBrowserPrivate
 {
 public:
     QtAvahiServiceBrowserPrivate(QtAvahiClient *client);
+    ~QtAvahiServiceBrowserPrivate();
 
     // Callback members
     static void callbackServiceTypeBrowser(AvahiServiceTypeBrowser *browser,
@@ -76,6 +77,7 @@ public:
     QtAvahiClient *client;
     AvahiServiceTypeBrowser *serviceTypeBrowser;
     QHash<QString, AvahiServiceBrowser *> serviceBrowserTable;
+    QList<AvahiServiceResolver *> m_serviceResolvers;
 };
 
 #endif // QTAVAHISERVICEBROWSERPRIVATE_H