Revert "Allow RENAME to a different case"

Always send the JOIN-PART couple because oragono might consider channels
name to be equivalent while clients would not. See
<ircv3/ircv3-specifications#420 (comment)>

This reverts commit 0103e14.

Author: hhirtz

irc/channelmanager.go

@@ -258,19 +258,19 @@ func (cm *ChannelManager) SetUnregistered(channelName string, account string) (e
 }
 
 // Rename renames a channel (but does not notify the members)
-func (cm *ChannelManager) Rename(name string, newName string) (caseOnly bool, err error) {
+func (cm *ChannelManager) Rename(name string, newName string) (err error) {
 	cfname, err := CasefoldChannel(name)
 	if err != nil {
-		return false, errNoSuchChannel
+		return errNoSuchChannel
 	}
 
 	newCfname, err := CasefoldChannel(newName)
 	if err != nil {
-		return false, errInvalidChannelName
+		return errInvalidChannelName
 	}
 	newSkeleton, err := Skeleton(newName)
 	if err != nil {
-		return false, errInvalidChannelName
+		return errInvalidChannelName
 	}
 
 	var channel *Channel
@@ -287,23 +287,15 @@ func (cm *ChannelManager) Rename(name string, newName string) (caseOnly bool, er
 	cm.Lock()
 	defer cm.Unlock()
 
-	if newCfname == cfname {
-		entry := cm.chans[cfname]
-		if entry == nil || !entry.channel.IsLoaded() {
-			return false, errNoSuchChannel
-		}
-		entry.channel.Rename(newName, cfname)
-		return true, nil
-	}
 	if cm.chans[newCfname] != nil || cm.registeredChannels.Has(newCfname) {
-		return false, errChannelNameInUse
+		return errChannelNameInUse
 	}
 	if cm.chansSkeletons.Has(newSkeleton) || cm.registeredSkeletons.Has(newSkeleton) {
-		return false, errChannelNameInUse
+		return errChannelNameInUse
 	}
 	entry := cm.chans[cfname]
 	if entry == nil || !entry.channel.IsLoaded() {
-		return false, errNoSuchChannel
+		return errNoSuchChannel
 	}
 	channel = entry.channel
 	info = channel.ExportRegistration(IncludeInitial)
@@ -324,7 +316,7 @@ func (cm *ChannelManager) Rename(name string, newName string) (caseOnly bool, er
 		cm.chans[cfname] = entry
 	}
 	entry.channel.Rename(newName, newCfname)
-	return false, nil
+	return nil
 }
 
 // Len returns the number of channels

irc/getters.go

@@ -453,11 +453,9 @@ func (channel *Channel) NameCasefolded() string {
 func (channel *Channel) Rename(name, nameCasefolded string) {
 	channel.stateMutex.Lock()
 	channel.name = name
-	if channel.nameCasefolded != nameCasefolded {
-		channel.nameCasefolded = nameCasefolded
-		if channel.registeredFounder != "" {
-			channel.registeredTime = time.Now().UTC()
-		}
+	channel.nameCasefolded = nameCasefolded
+	if channel.registeredFounder != "" {
+		channel.registeredTime = time.Now().UTC()
 	}
 	channel.stateMutex.Unlock()
 }

irc/handlers.go

@@ -2452,7 +2452,7 @@ func renameHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Re
 	}
 
 	// perform the channel rename
-	caseOnly, err := server.channels.Rename(oldName, newName)
+	err := server.channels.Rename(oldName, newName)
 	if err == errInvalidChannelName {
 		rb.Add(nil, server.name, ERR_NOSUCHCHANNEL, client.Nick(), utils.SafeErrorParam(newName), client.t(err.Error()))
 	} else if err == errChannelNameInUse {
@@ -2481,7 +2481,7 @@ func renameHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Re
 				} else {
 					targetRb.Add(nil, clientPrefix, "RENAME", oldName, newName)
 				}
-			} else if !caseOnly {
+			} else {
 				if reason != "" {
 					targetRb.Add(nil, targetPrefix, "PART", oldName, fmt.Sprintf(mcl.t("Channel renamed: %s"), reason))
 				} else {