Set pointers to NULL after free

Setting pointers to NULL after free never hurt, but may prevent
double free and other problems.
Signed-off-by: Juergen Kosel <juergen.kosel@softing.com>

src/LinkedList.c

@@ -218,7 +218,10 @@ static int ListUnlink(List* aList, void* content, int(*callback)(void*, void*),
 
 	next = aList->current->next;
 	if (freeContent)
+        {
 		free(aList->current->content);
+                aList->current->content = NULL;
+        }
 	if (saved == aList->current)
 		saveddeleted = 1;
 	free(aList->current);
@@ -357,7 +360,10 @@ void ListEmpty(List* aList)
 	{
 		ListElement* first = aList->first;
 		if (first->content != NULL)
+                {
 			free(first->content);
+                        first->content = NULL;
+                }
 		aList->first = first->next;
 		free(first);
 	}

src/MQTTAsync.c

@@ -1008,8 +1008,10 @@ static void MQTTAsync_freeServerURIs(MQTTAsyncs* m)
 
 	for (i = 0; i < m->serverURIcount; ++i)
 		free(m->serverURIs[i]);
+	m->serverURIcount = 0;
 	if (m->serverURIs)
 		free(m->serverURIs);
+	m->serverURIs = NULL;
 }
 
 
@@ -1023,7 +1025,9 @@ static void MQTTAsync_freeCommand1(MQTTAsync_queuedCommand *command)
 			free(command->command.details.sub.topics[i]);
 
 		free(command->command.details.sub.topics);
+		command->command.details.sub.topics = NULL;
 		free(command->command.details.sub.qoss);
+		command->command.details.sub.qoss = NULL;
 	}
 	else if (command->command.type == UNSUBSCRIBE)
 	{
@@ -1033,13 +1037,16 @@ static void MQTTAsync_freeCommand1(MQTTAsync_queuedCommand *command)
 			free(command->command.details.unsub.topics[i]);
 
 		free(command->command.details.unsub.topics);
+		command->command.details.unsub.topics = NULL;
 	}
 	else if (command->command.type == PUBLISH)
 	{
 		/* qos 1 and 2 topics are freed in the protocol code when the flows are completed */
 		if (command->command.details.pub.destinationName)
 			free(command->command.details.pub.destinationName);
+		command->command.details.pub.destinationName = NULL;
 		free(command->command.details.pub.payload);
+		command->command.details.pub.payload = NULL;
 	}
 }
 

src/MQTTProtocolClient.c

@@ -668,11 +668,13 @@ void MQTTProtocol_freeClient(Clients* client)
 	MQTTProtocol_freeMessageList(client->inboundMsgs);
 	ListFree(client->messageQueue);
 	free(client->clientID);
+        client->clientID = NULL;
 	if (client->will)
 	{
 		free(client->will->payload);
 		free(client->will->topic);
 		free(client->will);
+                client->will = NULL;
 	}
 #if defined(OPENSSL)
 	if (client->sslopts)
@@ -688,6 +690,7 @@ void MQTTProtocol_freeClient(Clients* client)
 		if (client->sslopts->enabledCipherSuites)
 			free((void*)client->sslopts->enabledCipherSuites);
 		free(client->sslopts);
+                client->sslopts = NULL;
 	}
 #endif
 	/* don't free the client structure itself... this is done elsewhere */

src/SSLSocket.c

@@ -855,7 +855,10 @@ int SSLSocket_putdatas(SSL* ssl, int socket, char* buf0, size_t buf0len, int cou
 		for (i = 0; i < count; ++i)
 		{
 			if (frees[i])
+                        {
 				free(buffers[i]);
+                                buffers[i] = NULL;
+                        }
 		}	
 	}
 	FUNC_EXIT_RC(rc); 

src/Socket.c

@@ -818,7 +818,10 @@ int Socket_continueWrite(int socket)
 			for (i = 0; i < pw->count; i++)
 			{
 				if (pw->frees[i])
+                                {
 					free(pw->iovecs[i].iov_base);
+                                        pw->iovecs[i].iov_base = NULL;
+                                }
 			}
 			rc = 1; /* signal complete */
 			Log(TRACE_MIN, -1, "ContinueWrite: partial write now complete for socket %d", socket);
@@ -834,7 +837,10 @@ int Socket_continueWrite(int socket)
 		for (i = 0; i < pw->count; i++)
 		{
 			if (pw->frees[i])
+                        {
 				free(pw->iovecs[i].iov_base);
+                                pw->iovecs[i].iov_base = NULL;
+                        }
 		}
 	}
 #if defined(OPENSSL)

src/SocketBuffer.c

@@ -106,6 +106,7 @@ void SocketBuffer_freeDefQ(void)
 {
 	free(def_queue->buf);
 	free(def_queue);
+        def_queue = NULL;
 }