Fix bad access bugs (hopefully)

In some callbacks, NSData objects to be passed to IRCClientSession's
event handlers would be nil (if e.g. a user parted a channel without
giving a reason). Those object references would then be sent messages.
This is bad. Instead, an NSData object is always allocated now, even
for blank reasons/messages/notices/etc. This object simply contains a
single null byte (i.e. it holds an empty, null-terminated C string).

IRCClient/IRCClientSession.h

 #pragma mark - Class methods
 /***************************/
 
+/**	Returns a dictionary of IRC numeric codes.
+ 
+	The dictionary contains entries for all known IRC numeric codes (as keys).
+	(The list is taken from https://www.alien.net.au/irc/irc2numerics.html .)
+	
+	The value for each key is an NSArray with the known numeric reply names for
+	which the numeric code is used.
+ 
+	Note that there is no gaurantee whatsoever that any given numeric reply 
+	name will, in fact, describe the contents of the message; most IRC numeric
+	messages have implementation-specific uses. See the various RFCs, and other
+	info sources, for details.
+ */
++(NSDictionary *)IRCNumericCodes;
+
 /** Set the nickname, username, and realname for the session.
  
 	Returns 1 if successfully set, 0 otherwise.

IRCClient/IRCClientSession.m

 
 #pragma mark - IRCClientSession private category declaration
 
+static NSDictionary* ircNumericCodeList;
+
 @interface IRCClientSession()
 {
 	irc_callbacks_t		_callbacks;
 
 @property (readwrite) NSMutableDictionary *channels;
 
++(void)loadNumericCodes;
+
 @end
 
 #pragma mark - IRCClientSession class implementation
 	irc_destroy_session(_irc_session);
 }
 
++(NSDictionary *)IRCNumericCodes
+{
+	if(ircNumericCodeList == nil)
+	{
+		[IRCClientSession loadNumericCodes];
+	}
+	
+	return ircNumericCodeList;
+}
+
++(void)loadNumericCodes
+{
+	NSString* numericCodeListPath = [[NSBundle mainBundle] pathForResource:@"IRC_Numerics" ofType:@"plist"];
+	ircNumericCodeList = [NSDictionary dictionaryWithContentsOfFile:numericCodeListPath];
+	if(ircNumericCodeList)
+	{
+		NSLog(@"IRC numeric codes list loaded successfully.\n");
+	}
+	else
+	{
+		NSLog(@"Could not load IRC numeric codes list!\n");
+	}
+}
+
 - (int)connect;
 {
 	return irc_connect(_irc_session, _server.UTF8String, (unsigned short) _port, (_password.length > 0 ? _password.SA_terminatedCString : NULL), _nickname.UTF8String, _username.UTF8String, _realname.UTF8String);
 	[_delegate privateMessageReceived:messageString fromUser:nick];
 }
 
-- (void)noticeSent:(NSData *)notice toChannel:(NSData *)channelName byUser:(NSString *)nick
+- (void)privateNoticeReceived:(NSData *)notice fromUser:(NSString *)nick
 {
-	IRCClientChannel *channel = _channels[channelName];
+	NSString* noticeString = [NSString stringWithCString:notice.SA_terminatedCString encoding:_encoding];
 	
-	[channel noticeSent:notice byUser:nick];
+	[_delegate privateNoticeReceived:noticeString fromUser:nick];
 }
 
-- (void)privateNoticeReceived:(NSData *)notice fromUser:(NSString *)nick
+- (void)noticeSent:(NSData *)notice toChannel:(NSData *)channelName byUser:(NSString *)nick
 {
-	NSString* noticeString = [NSString stringWithCString:notice.SA_terminatedCString encoding:_encoding];
+	IRCClientChannel *channel = _channels[channelName];
 	
-	[_delegate privateNoticeReceived:noticeString fromUser:nick];
+	[channel noticeSent:notice byUser:nick];
 }
 
 - (void)invitedToChannel:(NSData *)channelName by:(NSString *)nick
 {
-	[_delegate invitedToChannel:channelName by:nick];
+	[_delegate invitedToChannel:channelName.SA_dataWithTerminatedCString by:nick];
 }
 
 - (void)CTCPRequestReceived:(NSData *)request fromUser:(NSString *)nick
 	}
 	else if (!strcmp (the_request, "VERSION"))
 	{
-		irc_cmd_ctcp_reply (_irc_session, the_nick, [NSString stringWithFormat:@"VERSION %@", _version].UTF8String);
+		irc_cmd_ctcp_reply (_irc_session, the_nick, [[NSString stringWithFormat:@"VERSION %@", _version] cStringUsingEncoding:_encoding]);
 	}
 	else if (!strcmp (the_request, "FINGER"))
 	{
-		irc_cmd_ctcp_reply (_irc_session, the_nick, [NSString stringWithFormat:@"FINGER %@ (%@) Idle 0 seconds", _username, _realname].UTF8String);
+		irc_cmd_ctcp_reply (_irc_session, the_nick, [[NSString stringWithFormat:@"FINGER %@ (%@) Idle 0 seconds", _username, _realname] cStringUsingEncoding:_encoding]);
 	}
 	else if (!strcmp (the_request, "TIME"))
 	{
-		irc_cmd_ctcp_reply(_irc_session, the_nick, [[NSDate dateWithTimeIntervalSinceNow:0] descriptionWithCalendarFormat:@"TIME %a %b %e %H:%M:%S %Z %Y" timeZone:nil locale:[[NSUserDefaults standardUserDefaults] dictionaryRepresentation]].UTF8String);
+		irc_cmd_ctcp_reply(_irc_session, the_nick, [[[NSDate dateWithTimeIntervalSinceNow:0] descriptionWithCalendarFormat:@"TIME %a %b %e %H:%M:%S %Z %Y" timeZone:nil locale:[[NSUserDefaults standardUserDefaults] dictionaryRepresentation]] cStringUsingEncoding:_encoding]);
 	}
 	else
 	{
 			char* request_type = strtok(request_string, " ");
 			char* request_body = strtok(NULL, " " );
 			
-			[_delegate CTCPRequestReceived:[NSData dataWithBytes:request_body length:strlen(request_body) + 1] ofType:[NSData dataWithBytes:request_type length:strlen(request_type) + 1] fromUser:nick];
+			NSData* requestTypeData = [NSData dataWithBytes:request_body length:strlen(request_body) + 1];
+			NSData* requestBodyData = [NSData dataWithBytes:request_type length:strlen(request_type) + 1];
+			
+			[_delegate CTCPRequestReceived:requestBodyData.SA_dataWithTerminatedCString ofType:requestTypeData.SA_dataWithTerminatedCString fromUser:nick];
 			
 			free(request_string);
 		}
 
 - (void)CTCPReplyReceived:(NSData *)reply fromUser:(NSString *)nick
 {
-	[_delegate CTCPReplyReceived:reply fromUser:nick];
+	[_delegate CTCPReplyReceived:reply.SA_dataWithTerminatedCString fromUser:nick];
 }
 
 - (void)CTCPActionPerformed:(NSData *)action byUser:(NSString *)nick atTarget:(NSData *)target
 
 - (void)unknownEventReceived:(NSData *)event from:(NSString *)origin params:(NSArray *)params
 {
-	[_delegate unknownEventReceived:event from:origin params:params];
+	[_delegate unknownEventReceived:event.SA_dataWithTerminatedCString from:origin params:params];
 }
 
 -(void)numericEventReceived:(NSUInteger)event from:(NSString *)origin params:(NSArray *)params
 static void onQuit(irc_session_t *session, const char *event, const char *origin, const char **params, unsigned int count)
 {
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
-	
 	NSString *nick = @(origin);
+	
 	NSData *reason = nil;
 	if(count > 0)
 	{
-		reason = [[NSData alloc] initWithBytes:params[0] length:strlen(params[0]) + 1];
+		reason = [NSData dataWithBytes:params[0] length:strlen(params[0]) + 1];
+	}
+	else
+	{
+		reason = [NSData dataWithBytes:"\0" length:1];
 	}
 
 	[clientSession userQuit:nick withReason:reason];
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
 	NSString *nick = @(origin);
 	NSData *channelName = [NSData dataWithBytes:params[0] length:strlen(params[0]) + 1];
+
 	NSData *reason = nil;
-	
 	if (count > 1)
 	{
 		reason = [NSData dataWithBytes:params[1] length:strlen(params[1]) + 1];
 	}
+	else
+	{
+		reason = [NSData dataWithBytes:"\0" length:1];
+	}
 	
 	[clientSession userParted:nick channel:channelName withReason:reason];
 }
 	NSString *nick = @(origin);
 	NSData *channelName = [NSData dataWithBytes:params[0] length:strlen(params[0]) + 1];
 	NSString *mode = @(params[1]);
+
 	NSString *modeParams = nil;
-	
 	if (count > 2)
 	{
 		modeParams = @(params[2]);
 	}
+	else
+	{
+		modeParams = @"";
+	}
 	
 	[clientSession modeSet:mode withParams:modeParams forChannel:channelName by:nick];
 }
 	{
 		topic = [NSData dataWithBytes:params[1] length:strlen(params[1]) + 1];
 	}
+	else
+	{
+		topic = [NSData dataWithBytes:"\0" length:1];
+	}
 	
 	[clientSession topicSet:topic forChannel:channelName by:nick];
 }
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
 	NSString *byNick = @(origin);
 	NSData *channelName = [NSData dataWithBytes:params[0] length:strlen(params[0]) + 1];
+
 	NSString *nick = nil;
-	NSData *reason = nil;
-	
 	if (count > 1)
 	{
 		nick = @(params[1]);
 	}
 	
+	NSData *reason = nil;
 	if (count > 2)
 	{
 		reason = [NSData dataWithBytes:params[2] length:strlen(params[2]) + 1];
 	}
+	else
+	{
+		reason = [NSData dataWithBytes:"\0" length:1];
+	}
 	
 	[clientSession userKicked:nick fromChannel:channelName by:byNick withReason:reason];
 }
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
 	NSString *nick = @(origin);
 	NSData *channelName = [NSData dataWithBytes:params[0] length:strlen(params[0]) + 1];
-	NSData *message = nil;
 	
+	NSData *message = nil;
 	if (count > 1)
 	{
 		message = [NSData dataWithBytes:params[1] length:strlen(params[1]) + 1];
 	}
+	else
+	{
+		message = [NSData dataWithBytes:"\0" length:1];
+	}
 
 	[clientSession messageSent:message toChannel:channelName byUser:nick];
 }
 {
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
 	NSString *nick = @(origin);
+	
 	NSData *message = nil;
-
 	if (count > 1)
 	{
 		message = [NSData dataWithBytes:params[1] length:strlen(params[1]) + 1];
 	}
+	else
+	{
+		message = [NSData dataWithBytes:"\0" length:1];
+	}
 	
 	[clientSession privateMessageReceived:message fromUser:nick];
 }
 {
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
 	NSString *nick = @(origin);
-	NSData *notice = nil;
 	
+	NSData *notice = nil;
 	if (count > 1)
 	{
 		notice = [NSData dataWithBytes:params[1] length:strlen(params[1]) + 1];
 	}
+	else
+	{
+		notice = [NSData dataWithBytes:"\0" length:1];
+	}
 	
 	[clientSession privateNoticeReceived:notice fromUser:nick];
 }
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
 	NSString *nick = @(origin);
 	NSData *channelName = [NSData dataWithBytes:params[0] length:strlen(params[0]) + 1];
-	NSData *notice = nil;
 	
+	NSData *notice = nil;
 	if (count > 1)
 	{
 		notice = [NSData dataWithBytes:params[1] length:strlen(params[1]) + 1];
 	}
+	else
+	{
+		notice = [NSData dataWithBytes:"\0" length:1];
+	}
 
 	[clientSession noticeSent:notice toChannel:channelName byUser:nick];
 }
 static void onUnknownEvent(irc_session_t *session, const char *event, const char *origin, const char **params, unsigned int count)
 {
 	IRCClientSession *clientSession = (__bridge IRCClientSession *) irc_get_ctx(session);
-	NSData *eventString = [NSData dataWithBytes:event length:strlen(event) + 1];
-	NSString *sender = nil;
-	
+	NSData *eventData = [NSData dataWithBytes:event length:strlen(event) + 1];
+
+	NSString *originString = nil;
 	if (origin != NULL)
-		sender = @(origin);
+	{
+		originString = @(origin);
+	}
 	
 	NSMutableArray *paramsArray = [[NSMutableArray alloc] init];
-	
 	for (unsigned int i = 0; i < count; i++)
+	{
 		[paramsArray addObject:[NSData dataWithBytes:params[i] length:strlen(params[i]) + 1]];
+	}
 	
-	[clientSession unknownEventReceived:eventString from:sender params:[paramsArray copy]];
+	[clientSession unknownEventReceived:eventData from:originString params:paramsArray];
 }
 
 /*!
 	NSString *sender = @(origin);
 	
 	NSMutableArray *paramsArray = [[NSMutableArray alloc] init];
-	
 	for (unsigned int i = 0; i < count; i++)
+	{
 		[paramsArray addObject:[NSData dataWithBytes:params[i] length:strlen(params[i]) + 1]];
+	}
 	
-	[clientSession numericEventReceived:eventNumber from:sender params:[paramsArray copy]];
+	[clientSession numericEventReceived:eventNumber from:sender params:paramsArray];
 }