@@ -56,24 +56,51 @@
 #import "namespaces.h"
 
 #import <ObjFW/macros.h>
 
 #define BUFFER_LENGTH 512
+
+OF_ASSUME_NONNULL_BEGIN
+
+@interface XMPPConnection ()
+- (void)XMPP_startStream;
+- (void)XMPP_handleStream: (OFXMLElement *)element;
+- (void)XMPP_handleTLS: (OFXMLElement *)element;
+- (void)XMPP_handleSASL: (OFXMLElement *)element;
+- (void)XMPP_handleStanza: (OFXMLElement *)element;
+- (void)XMPP_sendAuth: (OFString *)authName;
+- (void)XMPP_sendResourceBind;
+- (void)XMPP_sendStreamError: (OFString *)condition
+			text: (nullable OFString *)text;
+- (void)XMPP_handleIQ: (XMPPIQ *)IQ;
+- (void)XMPP_handleMessage: (XMPPMessage *)message;
+- (void)XMPP_handlePresence: (XMPPPresence *)presence;
+- (void)XMPP_handleFeatures: (OFXMLElement *)element;
+- (void)XMPP_handleResourceBindForConnection: (XMPPConnection *)connection
+					  IQ: (XMPPIQ *)IQ;
+- (void)XMPP_sendSession;
+- (void)XMPP_handleSessionForConnection: (XMPPConnection *)connection
+				     IQ: (XMPPIQ *)IQ;
+- (OFString *)XMPP_IDNAToASCII: (OFString *)domain;
+- (XMPPMulticastDelegate *)XMPP_delegates;
+@end
 
 @interface XMPPConnection_ConnectThread: OFThread
 {
 	OFThread *_sourceThread;
 	XMPPConnection *_connection;
 }
 
-- initWithSourceThread: (OFThread*)sourceThread
-	    connection: (XMPPConnection*)connection;
+- initWithSourceThread: (OFThread *)sourceThread
+	    connection: (XMPPConnection *)connection;
 @end
+
+OF_ASSUME_NONNULL_END
 
 @implementation XMPPConnection_ConnectThread
-- initWithSourceThread: (OFThread*)sourceThread
-	    connection: (XMPPConnection*)connection
+- initWithSourceThread: (OFThread *)sourceThread
+	    connection: (XMPPConnection *)connection
 {
 	self = [super init];
 
 	@try {
 		_sourceThread = [sourceThread retain];
@@ -116,11 +143,13 @@
 	return nil;
 }
 @end
 
 @implementation XMPPConnection
-@synthesize language = _language, privateKeyFile = _privateKeyFile;
+@synthesize username = _username, resource = _resource, server = _server;
+@synthesize domain = _domain, password = _password, language = _language;
+@synthesize privateKeyFile = _privateKeyFile;
 @synthesize certificateFile = _certificateFile, socket = _socket;
 @synthesize encryptionRequired = _encryptionRequired, encrypted = _encrypted;
 @synthesize supportsRosterVersioning = _supportsRosterVersioning;
 @synthesize supportsStreamManagement = _supportsStreamManagement;
 
@@ -163,11 +192,11 @@
 	[_authModule release];
 
 	[super dealloc];
 }
 
-- (void)setUsername: (OFString*)username
+- (void)setUsername: (OFString *)username
 {
 	OFString *old = _username;
 
 	if (username != nil) {
 		char *node;
@@ -189,16 +218,11 @@
 		_username = nil;
 
 	[old release];
 }
 
-- (OFString*)username
-{
-	return [[_username copy] autorelease];
-}
-
-- (void)setResource: (OFString*)resource
+- (void)setResource: (OFString *)resource
 {
 	OFString *old = _resource;
 
 	if (resource != nil) {
 		char *res;
@@ -220,16 +244,11 @@
 		_resource = nil;
 
 	[old release];
 }
 
-- (OFString*)resource
-{
-	return [[_resource copy] autorelease];
-}
-
-- (void)setServer: (OFString*)server
+- (void)setServer: (OFString *)server
 {
 	OFString *old = _server;
 
 	if (server != nil)
 		_server = [self XMPP_IDNAToASCII: server];
@@ -237,16 +256,11 @@
 		_server = nil;
 
 	[old release];
 }
 
-- (OFString*)server
-{
-	return [[_server copy] autorelease];
-}
-
-- (void)setDomain: (OFString*)domain
+- (void)setDomain: (OFString *)domain
 {
 	OFString *oldDomain = _domain;
 	OFString *oldDomainToASCII = _domainToASCII;
 
 	if (domain != nil) {
@@ -274,16 +288,11 @@
 
 	[oldDomain release];
 	[oldDomainToASCII release];
 }
 
-- (OFString*)domain
-{
-	return [[_domain copy] autorelease];
-}
-
-- (void)setPassword: (OFString*)password
+- (void)setPassword: (OFString *)password
 {
 	OFString *old = _password;
 
 	if (password != nil) {
 		char *pass;
@@ -305,15 +314,10 @@
 		_password = nil;
 
 	[old release];
 }
 
-- (OFString*)password
-{
-	return [[_password copy] autorelease];
-}
-
 - (void)connect
 {
 	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
 	XMPPSRVEntry *candidate = nil;
 	XMPPSRVLookup *SRVLookup = nil;
@@ -380,11 +384,11 @@
 		      connection: self] autorelease] start];
 
 	[pool release];
 }
 
--  (bool)XMPP_parseBuffer: (const void*)buffer
+-  (bool)XMPP_parseBuffer: (const void *)buffer
 		   length: (size_t)length
 {
 	if ([_socket isAtEndOfStream]) {
 		[_delegates broadcastSelector: @selector(connectionWasClosed:)
 				   withObject: self];
@@ -402,11 +406,11 @@
 	}
 
 	return true;
 }
 
-- (void)parseBuffer: (const void*)buffer
+- (void)parseBuffer: (const void *)buffer
 	     length: (size_t)length
 {
 	[self XMPP_parseBuffer: buffer
 			length: length];
 
@@ -415,14 +419,14 @@
 
 	_oldParser = nil;
 	_oldElementBuilder = nil;
 }
 
--      (bool)stream: (OFStream*)stream
-  didReadIntoBuffer: (char*)buffer
+-      (bool)stream: (OFStream *)stream
+  didReadIntoBuffer: (char *)buffer
 	     length: (size_t)length
-	  exception: (OFException*)exception
+	  exception: (OFException *)exception
 {
 	if (exception != nil) {
 		[_delegates broadcastSelector: @selector(connection:
 						   didThrowException:)
 				   withObject: self
@@ -467,11 +471,11 @@
 - (bool)streamOpen
 {
 	return _streamOpen;
 }
 
-- (bool)checkCertificateAndGetReason: (OFString**)reason
+- (bool)checkCertificateAndGetReason: (OFString **)reason
 {
 	X509Certificate *cert;
 	OFDictionary *SANs;
 	bool serviceSpecific = false;
 
@@ -503,20 +507,20 @@
 		return true;
 
 	return false;
 }
 
-- (void)sendStanza: (OFXMLElement*)element
+- (void)sendStanza: (OFXMLElement *)element
 {
 	[_delegates broadcastSelector: @selector(connection:didSendElement:)
 			   withObject: self
 			   withObject: element];
 
 	[_socket writeString: [element XMLString]];
 }
 
--   (void)sendIQ: (XMPPIQ*)IQ
+-   (void)sendIQ: (XMPPIQ *)IQ
   callbackTarget: (id)target
 	selector: (SEL)selector
 {
 	OFAutoreleasePool *pool;
 	XMPPCallback *callback;
@@ -543,11 +547,11 @@
 
 	[self sendStanza: IQ];
 }
 
 #ifdef OF_HAVE_BLOCKS
--  (void)sendIQ: (XMPPIQ*)IQ
+-  (void)sendIQ: (XMPPIQ *)IQ
   callbackBlock: (xmpp_callback_block_t)block
 {
 	OFAutoreleasePool *pool;
 	XMPPCallback *callback;
 	OFString *ID, *key;
@@ -572,24 +576,21 @@
 
 	[self sendStanza: IQ];
 }
 #endif
 
-- (OFString*)generateStanzaID
+- (OFString *)generateStanzaID
 {
 	return [OFString stringWithFormat: @"objxmpp_%u", _lastID++];
 }
 
--    (void)parser: (OFXMLParser*)p
-  didStartElement: (OFString*)name
-	   prefix: (OFString*)prefix
-	namespace: (OFString*)ns
-       attributes: (OFArray*)attributes
-{
-	OFEnumerator *enumerator;
-	OFXMLAttribute *attribute;
-
+-    (void)parser: (OFXMLParser *)parser
+  didStartElement: (OFString *)name
+	   prefix: (OFString *)prefix
+	namespace: (OFString *)NS
+       attributes: (OFArray *)attributes
+{
 	if (![name isEqual: @"stream"]) {
 		// No dedicated stream error for this, may not even be XMPP
 		[self close];
 		[_socket close];
 		return;
@@ -599,18 +600,17 @@
 		[self XMPP_sendStreamError: @"bad-namespace-prefix"
 				      text: nil];
 		return;
 	}
 
-	if (![ns isEqual: XMPP_NS_STREAM]) {
+	if (![NS isEqual: XMPP_NS_STREAM]) {
 		[self XMPP_sendStreamError: @"invalid-namespace"
 				      text: nil];
 		return;
 	}
 
-	enumerator = [attributes objectEnumerator];
-	while ((attribute = [enumerator nextObject]) != nil) {
+	for (OFXMLAttribute *attribute in attributes) {
 		if ([[attribute name] isEqual: @"from"] &&
 		    ![[attribute stringValue] isEqual: _domain]) {
 			[self XMPP_sendStreamError: @"invalid-from"
 					      text: nil];
 			return;
@@ -621,15 +621,15 @@
 					      text: nil];
 			return;
 		}
 	}
 
-	[_parser setDelegate: _elementBuilder];
+	[parser setDelegate: _elementBuilder];
 }
 
-- (void)elementBuilder: (OFXMLElementBuilder*)builder
-       didBuildElement: (OFXMLElement*)element
+- (void)elementBuilder: (OFXMLElementBuilder *)builder
+       didBuildElement: (OFXMLElement *)element
 {
 	/* Ignore whitespace elements */
 	if ([element name] == nil)
 		return;
 
@@ -652,14 +652,14 @@
 
 	if ([[element namespace] isEqual: XMPP_NS_SASL])
 		[self XMPP_handleSASL: element];
 }
 
-- (void)elementBuilder: (OFXMLElementBuilder*)builder
-  didNotExpectCloseTag: (OFString*)name
-		prefix: (OFString*)prefix
-	     namespace: (OFString*)ns
+- (void)elementBuilder: (OFXMLElementBuilder *)builder
+  didNotExpectCloseTag: (OFString *)name
+		prefix: (OFString *)prefix
+	     namespace: (OFString *)ns
 {
 	if (![name isEqual: @"stream"] || ![prefix isEqual: @"stream"] ||
 	    ![ns isEqual: XMPP_NS_STREAM])
 		@throw [OFMalformedXMLException exception];
 	else {
@@ -720,11 +720,11 @@
 	_streamOpen = _needsSession = _encrypted = false;
 	_supportsRosterVersioning = _supportsStreamManagement = false;
 	_lastID = 0;
 }
 
-- (void)XMPP_handleStanza: (OFXMLElement*)element
+- (void)XMPP_handleStanza: (OFXMLElement *)element
 {
 	if ([[element name] isEqual: @"iq"]) {
 		[self XMPP_handleIQ: [XMPPIQ stanzaWithElement: element]];
 		return;
 	}
@@ -744,11 +744,11 @@
 	[self XMPP_sendStreamError: @"unsupported-stanza-type"
 			      text: nil];
 }
 
 
-- (void)XMPP_handleStream: (OFXMLElement*)element
+- (void)XMPP_handleStream: (OFXMLElement *)element
 {
 	if ([[element name] isEqual: @"features"]) {
 		[self XMPP_handleFeatures: element];
 		return;
 	}
@@ -848,11 +848,11 @@
 	}
 
 	assert(0);
 }
 
-- (void)XMPP_handleTLS: (OFXMLElement*)element
+- (void)XMPP_handleTLS: (OFXMLElement *)element
 {
 	if ([[element name] isEqual: @"proceed"]) {
 		/* FIXME: Catch errors here */
 		SSLSocket *newSock;
 
@@ -889,11 +889,11 @@
 		@throw [OFException exception];
 
 	assert(0);
 }
 
-- (void)XMPP_handleSASL: (OFXMLElement*)element
+- (void)XMPP_handleSASL: (OFXMLElement *)element
 {
 	if ([[element name] isEqual: @"challenge"]) {
 		OFXMLElement *responseTag;
 		OFDataArray *challenge = [OFDataArray
 		    dataArrayWithBase64EncodedString: [element stringValue]];
@@ -937,11 +937,11 @@
 	}
 
 	assert(0);
 }
 
-- (void)XMPP_handleIQ: (XMPPIQ*)IQ
+- (void)XMPP_handleIQ: (XMPPIQ *)IQ
 {
 	bool handled = false;
 	XMPPCallback *callback;
 	OFString *key;
 
@@ -968,25 +968,25 @@
 		[self sendStanza: [IQ errorIQWithType: @"cancel"
 					    condition: @"service-unavailable"]];
 	}
 }
 
-- (void)XMPP_handleMessage: (XMPPMessage*)message
+- (void)XMPP_handleMessage: (XMPPMessage *)message
 {
 	[_delegates broadcastSelector: @selector(connection:didReceiveMessage:)
 			   withObject: self
 			   withObject: message];
 }
 
-- (void)XMPP_handlePresence: (XMPPPresence*)presence
+- (void)XMPP_handlePresence: (XMPPPresence *)presence
 {
 	[_delegates broadcastSelector: @selector(connection:didReceivePresence:)
 			   withObject: self
 			   withObject: presence];
 }
 
-- (void)XMPP_handleFeatures: (OFXMLElement*)element
+- (void)XMPP_handleFeatures: (OFXMLElement *)element
 {
 	OFXMLElement *startTLS = [element elementForName: @"starttls"
 					       namespace: XMPP_NS_STARTTLS];
 	OFXMLElement *bind = [element elementForName: @"bind"
 					   namespace: XMPP_NS_BIND];
@@ -1021,11 +1021,11 @@
 
 		enumerator = [[mechs children] objectEnumerator];
 		while ((mech = [enumerator nextObject]) != nil)
 			[mechanisms addObject: [mech stringValue]];
 
-		if (_privateKeyFile && _certificateFile &&
+		if (_privateKeyFile != nil && _certificateFile != nil &&
 		    [mechanisms containsObject: @"EXTERNAL"]) {
 			_authModule = [[XMPPEXTERNALAuth alloc] init];
 			[self XMPP_sendAuth: @"EXTERNAL"];
 			return;
 		}
@@ -1061,12 +1061,12 @@
 		}
 
 		assert(0);
 	}
 
-	if (session != nil && ![session elementForName: @"optional"
-					     namespace: XMPP_NS_SESSION])
+	if (session != nil && [session elementForName: @"optional"
+					    namespace: XMPP_NS_SESSION] == nil)
 		_needsSession = true;
 
 	if (bind != nil) {
 		[self XMPP_sendResourceBind];
 		return;
@@ -1073,11 +1073,11 @@
 	}
 
 	assert(0);
 }
 
-- (void)XMPP_sendAuth: (OFString*)authName
+- (void)XMPP_sendAuth: (OFString *)authName
 {
 	OFXMLElement *authTag;
 	OFDataArray *initialMessage = [_authModule initialMessage];
 
 	authTag = [OFXMLElement elementWithName: @"auth"
@@ -1117,12 +1117,12 @@
 	    callbackTarget: self
 		  selector: @selector(XMPP_handleResourceBindForConnection:
 				IQ:)];
 }
 
-- (void)XMPP_sendStreamError: (OFString*)condition
-			text: (OFString*)text
+- (void)XMPP_sendStreamError: (OFString *)condition
+			text: (OFString *)text
 {
 	OFXMLElement *error = [OFXMLElement
 	    elementWithName: @"error"
 		  namespace: XMPP_NS_STREAM];
 	[error setPrefix: @"stream"
@@ -1137,26 +1137,25 @@
 	[_parser setDelegate: nil];
 	[self sendStanza: error];
 	[self close];
 }
 
-- (void)XMPP_handleResourceBindForConnection: (XMPPConnection*)connection
-					  IQ: (XMPPIQ*)iq
-{
-	OFXMLElement *bindElement;
-	OFXMLElement *jidElement;
-
-	assert([[iq type] isEqual: @"result"]);
-
-	bindElement = [iq elementForName: @"bind"
+- (void)XMPP_handleResourceBindForConnection: (XMPPConnection *)connection
+					  IQ: (XMPPIQ *)IQ
+{
+	OFXMLElement *bindElement, *JIDElement;
+
+	assert([[IQ type] isEqual: @"result"]);
+
+	bindElement = [IQ elementForName: @"bind"
 			       namespace: XMPP_NS_BIND];
 
 	assert(bindElement != nil);
 
-	jidElement = [bindElement elementForName: @"jid"
+	JIDElement = [bindElement elementForName: @"jid"
 				       namespace: XMPP_NS_BIND];
-	_JID = [[XMPPJID alloc] initWithString: [jidElement stringValue]];
+	_JID = [[XMPPJID alloc] initWithString: [JIDElement stringValue]];
 
 	if (_needsSession) {
 		[self XMPP_sendSession];
 		return;
 	}
@@ -1166,33 +1165,33 @@
 			   withObject: _JID];
 }
 
 - (void)XMPP_sendSession
 {
-	XMPPIQ *iq;
+	XMPPIQ *IQ = [XMPPIQ IQWithType: @"set"
+				     ID: [self generateStanzaID]];
 
-	iq = [XMPPIQ IQWithType: @"set"
-			     ID: [self generateStanzaID]];
-	[iq addChild: [OFXMLElement elementWithName: @"session"
+	[IQ addChild: [OFXMLElement elementWithName: @"session"
 					  namespace: XMPP_NS_SESSION]];
-	[self	    sendIQ: iq
+
+	[self	    sendIQ: IQ
 	    callbackTarget: self
 		  selector: @selector(XMPP_handleSessionForConnection:IQ:)];
 }
 
-- (void)XMPP_handleSessionForConnection: (XMPPConnection*)connection
-				     IQ: (XMPPIQ*)iq
+- (void)XMPP_handleSessionForConnection: (XMPPConnection *)connection
+				     IQ: (XMPPIQ *)IQ
 {
-	if (![[iq type] isEqual: @"result"])
-		assert(0);
+	if (![[IQ type] isEqual: @"result"])
+		OF_ENSURE(0);
 
 	[_delegates broadcastSelector: @selector(connection:wasBoundToJID:)
 			   withObject: self
 			   withObject: _JID];
 }
 
-- (OFString*)XMPP_IDNAToASCII: (OFString*)domain
+- (OFString *)XMPP_IDNAToASCII: (OFString *)domain
 {
 	OFString *ret;
 	char *cDomain;
 	Idna_rc rc;
 
@@ -1234,10 +1233,10 @@
 - (void)removeDelegate: (id <XMPPConnectionDelegate>)delegate
 {
 	[_delegates removeDelegate: delegate];
 }
 
-- (XMPPMulticastDelegate*)XMPP_delegates
+- (XMPPMulticastDelegate *)XMPP_delegates
 {
 	return _delegates;
 }
 @end