Fix a few bugs in roster versioning.

src/XMPPJSONFileStorage.m

@@ -39,7 +39,8 @@
 {
 	Class c = isa;
 	[self release];
-	@throw [OFNotImplementedException exceptionWithClass: c];
+	@throw [OFNotImplementedException exceptionWithClass: c
+						    selector: _cmd];
 }
 
 - initWithFile: (OFString*)file_
@@ -103,8 +104,11 @@
 		iter = iter2;
 	}
 
-	[iter setObject: object
+	if (object != nil)
-		 forKey: [pathComponents lastObject]];
+		[iter setObject: object
+			 forKey: [pathComponents lastObject]];
+	else
+		[iter removeObjectForKey: [pathComponents lastObject]];
 }
 
 - (id)XMPP_objectForPath: (OFString*)path

src/XMPPRoster.m

@@ -133,6 +133,7 @@
 		    [[rosterElement attributeForName: @"ver"] stringValue];
 		[dataStorage setStringValue: ver
 				    forPath: @"roster.ver"];
+		[dataStorage save];
 	}
 
 	[delegates broadcastSelector: @selector(
@@ -228,6 +229,9 @@
 		OFMutableDictionary *items = [[[dataStorage dictionaryForPath:
 		    @"roster.items"] mutableCopy] autorelease];
 
+		if (items == nil)
+			items = [OFMutableDictionary dictionary];
+
 		if (![[rosterItem subscription] isEqual: @"remove"]) {
 			OFMutableDictionary *item = [OFMutableDictionary
 			    dictionaryWithKeysAndObjects:
@@ -342,6 +346,7 @@
 		    [[rosterElement attributeForName: @"ver"] stringValue];
 		[dataStorage setStringValue: ver
 				    forPath: @"roster.ver"];
+		[dataStorage save];
 	}
 
 	[delegates broadcastSelector: @selector(rosterWasReceived:)

tests/test.m

@@ -32,6 +32,7 @@
 #import "XMPPMessage.h"
 #import "XMPPPresence.h"
 #import "XMPPRoster.h"
+#import "XMPPJSONFileStorage.h"
 
 @interface AppDelegate: OFObject
 #ifdef OF_HAVE_OPTIONAL_PROTOCOLS
@@ -92,10 +93,15 @@ OF_APPLICATION_DELEGATE(AppDelegate)
 	    [[stanza from] fullJID], [[stanza to] fullJID], [stanza type],
 	    [stanza ID]] isEqual: @"bob@localhost, alice@localhost, get, 42"]));
 
-	conn = [[XMPPConnection alloc] init];
-	roster = [[XMPPRoster alloc] initWithConnection: conn];
 
+	conn = [[XMPPConnection alloc] init];
 	[conn addDelegate: self];
+
+	XMPPJSONFileStorage *storage =
+	    [[XMPPJSONFileStorage alloc] initWithFile: @"storage.json"];
+	[conn setDataStorage: storage];
+
+	roster = [[XMPPRoster alloc] initWithConnection: conn];
 	[roster addDelegate: self];
 
 	if ([arguments count] != 3) {