Index: src/XMPPConnection.h
==================================================================
--- src/XMPPConnection.h
+++ src/XMPPConnection.h
@@ -155,11 +155,11 @@
 	OFMutableDictionary *callbacks;
 	XMPPAuthenticator *authModule;
 	BOOL streamOpen;
 	BOOL needsSession;
 	BOOL encryptionRequired, encrypted;
-	BOOL rosterVersioningSupported;
+	BOOL supportsRosterVersioning;
 	unsigned int lastID;
 /// \endcond
 }
 
 #ifdef OF_HAVE_PROPERTIES
@@ -194,11 +194,11 @@
 /// \brief Whether encryption is required
 @property BOOL encryptionRequired;
 /// \brief Whether the connection is encrypted
 @property (readonly) BOOL encrypted;
 /// \brief Whether roster versioning is supported
-@property (readonly) BOOL rosterVersioningSupported;
+@property (readonly) BOOL supportsRosterVersioning;
 #endif
 
 /**
  * \brief Creates a new autoreleased XMPPConnection.
  *
@@ -336,11 +336,11 @@
 - (uint16_t)port;
 - (void)setDataStorage: (id <XMPPStorage>)dataStorage;
 - (id <XMPPStorage>)dataStorage;
 - (void)setLanguage: (OFString*)language;
 - (OFString*)language;
-- (BOOL)rosterVersioningSupported;
+- (BOOL)supportsRosterVersioning;
 
 /// \cond internal
 - (void)XMPP_startStream;
 - (void)XMPP_handleStream: (OFXMLElement*)element;
 - (void)XMPP_handleTLS: (OFXMLElement*)element;

Index: src/XMPPConnection.m
==================================================================
--- src/XMPPConnection.m
+++ src/XMPPConnection.m
@@ -348,13 +348,13 @@
 - (BOOL)streamOpen
 {
 	return streamOpen;
 }
 
-- (BOOL)rosterVersioningSupported
+- (BOOL)supportsRosterVersioning
 {
-	return rosterVersioningSupported;
+	return supportsRosterVersioning;
 }
 
 - (BOOL)checkCertificateAndGetReason: (OFString**)reason
 {
 	X509Certificate *cert;
@@ -850,11 +850,11 @@
 		/* TODO: Find/create an exception to throw here */
 		@throw [OFException exceptionWithClass: isa];
 
 	if ([element elementForName: @"ver"
 			  namespace: XMPP_NS_ROSTERVER] != nil)
-		rosterVersioningSupported = YES;
+		supportsRosterVersioning = YES;
 
 	if (mechs != nil) {
 		OFEnumerator *enumerator;
 		OFXMLElement *mech;
 

Index: src/XMPPRoster.h
==================================================================
--- src/XMPPRoster.h
+++ src/XMPPRoster.h
@@ -145,16 +145,14 @@
 
 - (void)setDataStorage: (id <XMPPStorage>)dataStorage;
 - (id <XMPPStorage>)dataStorage;
 
 /// \cond internal
-- (void)XMPP_addRosterItem: (XMPPRosterItem*)rosterItem;
 - (void)XMPP_updateRosterItem: (XMPPRosterItem*)rosterItem;
-- (void)XMPP_deleteRosterItem: (XMPPRosterItem*)rosterItem;
 - (void)XMPP_handleInitialRosterForConnection: (XMPPConnection*)connection
 				       withIQ: (XMPPIQ*)iq;
 - (XMPPRosterItem*)XMPP_rosterItemWithXMLElement: (OFXMLElement*)element;
 /// \endcond
 @end
 
 @interface OFObject (XMPPRosterDelegate) <XMPPRosterDelegate>
 @end

Index: src/XMPPRoster.m
==================================================================
--- src/XMPPRoster.m
+++ src/XMPPRoster.m
@@ -73,17 +73,32 @@
 }
 
 - (void)requestRoster
 {
 	XMPPIQ *iq;
+	OFXMLElement *query;
 
 	rosterRequested = YES;
 
 	iq = [XMPPIQ IQWithType: @"get"
 			     ID: [connection generateStanzaID]];
-	[iq addChild: [OFXMLElement elementWithName: @"query"
-					  namespace: XMPP_NS_ROSTER]];
+
+	query = [OFXMLElement elementWithName: @"query"
+				    namespace: XMPP_NS_ROSTER];
+
+	if ([connection supportsRosterVersioning]) {
+		OFString *ver = [dataStorage stringValueForPath: @"roster.ver"];
+
+		if (ver == nil)
+			ver = @"";
+
+		[query addAttributeWithName: @"ver"
+				stringValue: ver];
+	}
+
+	[iq addChild: query];
+
 	[connection     sendIQ: iq
 	    withCallbackObject: self
 		      selector: @selector(XMPP_handleInitialRosterForConnection:
 			withIQ:)];
 }
@@ -108,20 +123,24 @@
 				      namespace: XMPP_NS_ROSTER];
 
 	if (element != nil) {
 		rosterItem = [self XMPP_rosterItemWithXMLElement: element];
 
-		if ([[rosterItem subscription] isEqual: @"remove"])
-			[self XMPP_deleteRosterItem: rosterItem];
-		else
-			[self XMPP_addRosterItem: rosterItem];
-
-		[delegates broadcastSelector: @selector(
-						  roster:didReceiveRosterItem:)
-				  withObject: self
-				  withObject: rosterItem];
-	}
+		[self XMPP_updateRosterItem: rosterItem];
+	}
+
+	if ([connection supportsRosterVersioning]) {
+		OFString *ver =
+		    [[rosterElement attributeForName: @"ver"] stringValue];
+		[dataStorage setStringValue: ver
+				    forPath: @"roster.ver"];
+	}
+
+	[delegates broadcastSelector: @selector(
+					  roster:didReceiveRosterItem:)
+			  withObject: self
+			  withObject: rosterItem];
 
 	[connection_ sendStanza: [iq resultIQ]];
 
 	return YES;
 }
@@ -201,24 +220,45 @@
 - (id <XMPPStorage>)dataStorage
 {
 	return dataStorage;
 }
 
-- (void)XMPP_addRosterItem: (XMPPRosterItem*)rosterItem
-{
-	return [self XMPP_updateRosterItem: rosterItem];
-}
-
 - (void)XMPP_updateRosterItem: (XMPPRosterItem*)rosterItem
 {
-	[rosterItems setObject: rosterItem
-			forKey: [[rosterItem JID] bareJID]];
-}
+	if ([connection supportsRosterVersioning]) {
+		OFMutableDictionary *items = [[[dataStorage dictionaryForPath:
+		    @"roster.items"] mutableCopy] autorelease];
+
+		if (![[rosterItem subscription] isEqual: @"remove"]) {
+			OFMutableDictionary *item = [OFMutableDictionary
+			    dictionaryWithKeysAndObjects:
+			    @"JID", [[rosterItem JID] bareJID],
+			    @"subscription", [rosterItem subscription],
+			    nil];
+
+			if ([rosterItem name] != nil)
+				[item setObject: [rosterItem name]
+					 forKey: @"name"];
+
+			if ([rosterItem groups] != nil)
+				[item setObject: [rosterItem groups]
+					 forKey: @"groups"];
+
+			[items setObject: item
+				  forKey: [[rosterItem JID] bareJID]];
+		} else
+			[items removeObjectForKey: [[rosterItem JID] bareJID]];
+
+		[dataStorage setDictionary: items
+				   forPath: @"roster.items"];
+	}
 
-- (void)XMPP_deleteRosterItem: (XMPPRosterItem*)rosterItem
-{
-	[rosterItems removeObjectForKey: [[rosterItem JID] bareJID]];
+	if (![[rosterItem subscription] isEqual: @"remove"])
+		[rosterItems setObject: rosterItem
+				forKey: [[rosterItem JID] bareJID]];
+	else
+		[rosterItems removeObjectForKey: [[rosterItem JID] bareJID]];
 }
 
 - (XMPPRosterItem*)XMPP_rosterItemWithXMLElement: (OFXMLElement*)element
 {
 	OFString *subscription;
@@ -253,33 +293,57 @@
 		[rosterItem setGroups: groups];
 
 	return rosterItem;
 }
 
-- (void)XMPP_handleInitialRosterForConnection: (XMPPConnection*)connection
+- (void)XMPP_handleInitialRosterForConnection: (XMPPConnection*)connection_
 				       withIQ: (XMPPIQ*)iq
 {
 	OFXMLElement *rosterElement;
 	OFEnumerator *enumerator;
 	OFXMLElement *element;
-	XMPPRosterItem *rosterItem = nil;
+	XMPPRosterItem *rosterItem;
 
 	rosterElement = [iq elementForName: @"query"
 				 namespace: XMPP_NS_ROSTER];
+
+	if ([connection supportsRosterVersioning]) {
+		OFDictionary *items = [dataStorage
+		    dictionaryForPath: @"roster.items"];
+		OFEnumerator *enumerator = [items objectEnumerator];
+		OFDictionary *item;
+
+		while ((item = [enumerator nextObject]) != nil) {
+			rosterItem = [XMPPRosterItem rosterItem];
+			[rosterItem setJID: [XMPPJID JIDWithString:
+			    [item objectForKey: @"JID"]]];
+			[rosterItem setName: [item objectForKey: @"name"]];
+			[rosterItem setSubscription:
+			    [item objectForKey: @"subscription"]];
+			[rosterItem setGroups: [item objectForKey: @"groups"]];
+
+			[rosterItems setObject: rosterItem
+					forKey: [[rosterItem JID] bareJID]];
+		}
+	}
 
 	enumerator = [[rosterElement children] objectEnumerator];
 	while ((element = [enumerator nextObject]) != nil) {
 		if (![[element name] isEqual: @"item"] ||
 		    ![[element namespace] isEqual: XMPP_NS_ROSTER])
 			continue;
 
 		rosterItem = [self XMPP_rosterItemWithXMLElement: element];
 
-		if ([[rosterItem subscription] isEqual: @"remove"])
-			[self XMPP_deleteRosterItem: rosterItem];
-		else
-			[self XMPP_addRosterItem: rosterItem];
+		[self XMPP_updateRosterItem: rosterItem];
+	}
+
+	if ([connection supportsRosterVersioning]) {
+		OFString *ver =
+		    [[rosterElement attributeForName: @"ver"] stringValue];
+		[dataStorage setStringValue: ver
+				    forPath: @"roster.ver"];
 	}
 
 	[delegates broadcastSelector: @selector(rosterWasReceived:)
 			  withObject: self];
 }

Index: src/XMPPRosterItem.m
==================================================================
--- src/XMPPRosterItem.m
+++ src/XMPPRosterItem.m
@@ -23,10 +23,12 @@
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
 
 #import "XMPPRosterItem.h"
+
+#import <ObjFW/macros.h>
 
 @implementation XMPPRosterItem
 + rosterItem
 {
 	return [[[self alloc] init] autorelease];
@@ -102,15 +104,13 @@
 	return [[subscription copy] autorelease];
 }
 
 - (void)setGroups: (OFArray*)groups_
 {
-	OFArray *old = groups;
-	groups = [groups_ copy];
-	[old release];
+	OF_SETTER(groups, groups_, YES, YES)
 }
 
 - (OFArray*)groups
 {
-	return [[groups copy] autorelease];
+	OF_GETTER(groups, YES)
 }
 @end