From ebc3e67bf427f4210264c2259ea2887bca745fee Mon Sep 17 00:00:00 2001
From: Alexander Golubev <fatzer2@gmail.com>
Date: Wed, 13 Mar 2024 19:50:28 +0300
Subject: [PATCH] Workaround crashes caused by some slots deleting the sender

Signed-off-by: Alexander Golubev <fatzer2@gmail.com>
---
 src/kernel/ntqobject.h     |  2 +-
 src/kernel/ntqobjectdefs.h |  2 +-
 src/kernel/qobject.cpp     | 32 ++++++++++++++++++++++++++------
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/src/kernel/ntqobject.h b/src/kernel/ntqobject.h
index fc16c50b..cc5d5c89 100644
--- a/src/kernel/ntqobject.h
+++ b/src/kernel/ntqobject.h
@@ -210,7 +210,7 @@ private:
     const char	*objname;
     TQObject	*parentObj;
     TQObjectList *childObjects;
-    TQSignalVec *connections;
+    TQObjectSignalVec *connections;
     TQSenderObjectList *senderObjects;
     TQObjectList *eventFilters;
     TQPostEventList *postedEvents;
diff --git a/src/kernel/ntqobjectdefs.h b/src/kernel/ntqobjectdefs.h
index ba5e12b8..53f7e806 100644
--- a/src/kernel/ntqobjectdefs.h
+++ b/src/kernel/ntqobjectdefs.h
@@ -155,7 +155,7 @@ class TQMutex;
 struct TQMetaData;
 class TQConnectionList;
 class TQConnectionListIt;
-class TQSignalVec;
+class TQObjectSignalVec;
 class TQObjectList;
 class TQObjectListIt;
 class TQMemberDict;
diff --git a/src/kernel/qobject.cpp b/src/kernel/qobject.cpp
index 44971cfe..6b28b15f 100644
--- a/src/kernel/qobject.cpp
+++ b/src/kernel/qobject.cpp
@@ -88,6 +88,14 @@ class TQStyleControlElementDataPrivate {
 		bool isTQWidget;
 };
 
+// A thin wrapper around TQSignalVec, which is technicly public, but shouldn't be
+class TQObjectSignalVec: public TQSignalVec, public TQShared
+{
+public:
+    TQObjectSignalVec(int size=17 ): TQSignalVec(size)
+    { setAutoDelete(TRUE); }
+};
+
 #ifndef TQT_NO_USERDATA
 class TQObjectPrivate : public TQPtrVector<TQObjectUserData>
 #else
@@ -773,8 +781,10 @@ TQObject::~TQObject()
 		}
 	    }
 	}
-	delete connections;
-	connections = 0;
+	if ( connections->deref() ) {
+	    delete connections;
+	    connections = 0;
+	}
     }
     if ( eventFilters ) {
 	delete eventFilters;
@@ -1606,8 +1616,7 @@ TQConnectionList *TQObject::receivers( int signal ) const
     if ( tqt_preliminary_signal_spy && signal >= 0 ) {
 	if ( !connections ) {
 	    TQObject* that = (TQObject*) this;
-	    that->connections = new TQSignalVec( signal+1 );
-	    that->connections->setAutoDelete( TRUE );
+	    that->connections = new TQObjectSignalVec( signal+1 );
 	}
 	if ( !connections->at( signal ) ) {
 	    TQConnectionList* clist = new TQConnectionList;
@@ -2242,9 +2251,8 @@ void TQObject::connectInternal( const TQObject *sender, int signal_index, const
     TQObject *r = (TQObject*)receiver;
 
     if ( !s->connections ) {			// create connections lookup table
-	s->connections = new TQSignalVec( signal_index+1 );
+	s->connections = new TQObjectSignalVec( signal_index+1 );
 	TQ_CHECK_PTR( s->connections );
-	s->connections->setAutoDelete( TRUE );
     }
 
     TQConnectionList *clist = s->connections->at( signal_index );
@@ -2785,6 +2793,13 @@ void TQObject::activate_signal( TQConnectionList *clist, TQUObject *o )
     const TQThread *currentThread = TQThread::currentThreadObject();
 #endif // TQT_THREAD_SUPPORT
 
+    // Some slots are deleting the sender. It's not that great, but it's widespread enough,
+    // so we can't track all such issues. So, we have to workaround this somehow.
+    // For that we are postponing the deletion of clist (which is part of connections).
+    Q_ASSERT(connections);
+    TQObjectSignalVec *conn = connections;
+    conn->ref();
+
     const TQConnection *cd = 0;
     for(const TQConnection *c: *clist) {
 	Q_ASSERT( c );
@@ -2862,6 +2877,11 @@ void TQObject::activate_signal( TQConnectionList *clist, TQUObject *o )
 	if (sol) sol->listMutex->unlock();
 #endif // TQT_THREAD_SUPPORT
     }
+
+    // use a copy of the pointer here as at this point this might be already deleted; no pun intended ;)
+    if( conn->deref() ) {
+	delete conn;
+    }
 }
 
 /*!