From a7947d3c87a9871b0a84f7f2734fc1e5904c4d1c Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Mon, 16 Jul 2018 15:49:59 +0200
Subject: [PATCH] Connection guard, only valid signal connections will be added

---
 src/blackmisc/connectionguard.cpp | 14 +++++++++++---
 src/blackmisc/connectionguard.h   |  6 +++---
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/blackmisc/connectionguard.cpp b/src/blackmisc/connectionguard.cpp
index 9a2924a83..071c10c9a 100644
--- a/src/blackmisc/connectionguard.cpp
+++ b/src/blackmisc/connectionguard.cpp
@@ -17,14 +17,22 @@ namespace BlackMisc
         m_connections.append(connection);
     }
 
-    void CConnectionGuard::append(const QMetaObject::Connection &connection)
+    bool CConnectionGuard::append(const QMetaObject::Connection &connection)
     {
+        if (!connection) { return false; }
         m_connections.append(connection);
+        return true;
     }
 
-    void CConnectionGuard::append(const QList<QMetaObject::Connection> &connections)
+    bool CConnectionGuard::append(const QList<QMetaObject::Connection> &connections)
     {
-        m_connections.append(connections);
+        int c = 0;
+        for (const QMetaObject::Connection &connection : connections)
+        {
+            if (!connection) { continue; }
+            if (this->append(connection)) { c++; }
+        }
+        return c > 0;
     }
 
     CConnectionGuard::~CConnectionGuard()
diff --git a/src/blackmisc/connectionguard.h b/src/blackmisc/connectionguard.h
index cf6ab8b66..8cd8d3323 100644
--- a/src/blackmisc/connectionguard.h
+++ b/src/blackmisc/connectionguard.h
@@ -50,10 +50,10 @@ namespace BlackMisc
         ~CConnectionGuard();
 
         //! Add connection
-        void append(const QMetaObject::Connection &connection);
+        bool append(const QMetaObject::Connection &connection);
 
         //! Add connections
-        void append(const QList<QMetaObject::Connection> &connections);
+        bool append(const QList<QMetaObject::Connection> &connections);
 
         //! Disconnect all
         int disconnectAll();
@@ -61,6 +61,6 @@ namespace BlackMisc
     private:
         QList<QMetaObject::Connection> m_connections;
     };
-} // BlackMisc
+} // ns
 
 #endif