From 28d4971f366e9cb101a37f3904f605cf093dc549 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Fri, 24 Jul 2020 02:37:36 -0400
Subject: [PATCH] fix #1204

---
 irc/channel.go        | 35 +++++------------------------------
 irc/handlers.go       | 25 ++++++-------------------
 irc/responsebuffer.go | 17 +++++++++++++++++
 3 files changed, 28 insertions(+), 49 deletions(-)

diff --git a/irc/channel.go b/irc/channel.go
index 30ab0db5..483a8009 100644
--- a/irc/channel.go
+++ b/irc/channel.go
@@ -1246,44 +1246,19 @@ func (channel *Channel) SendSplitMessage(command string, minPrefixMode modes.Mod
 	}
 
 	// send echo-message
-	if rb.session.capabilities.Has(caps.EchoMessage) {
-		var tagsToUse map[string]string
-		if rb.session.capabilities.Has(caps.MessageTags) {
-			tagsToUse = clientOnlyTags
-		}
-		if histType == history.Tagmsg && rb.session.capabilities.Has(caps.MessageTags) {
-			rb.AddFromClient(message.Time, message.Msgid, details.nickMask, details.accountName, tagsToUse, command, chname)
-		} else {
-			rb.AddSplitMessageFromClient(details.nickMask, details.accountName, tagsToUse, command, chname, message)
-		}
-	}
-	// send echo-message to other connected sessions
-	for _, session := range client.Sessions() {
-		if session == rb.session {
-			continue
-		}
-		var tagsToUse map[string]string
-		if session.capabilities.Has(caps.MessageTags) {
-			tagsToUse = clientOnlyTags
-		}
-		if histType == history.Tagmsg && session.capabilities.Has(caps.MessageTags) {
-			session.sendFromClientInternal(false, message.Time, message.Msgid, details.nickMask, details.accountName, tagsToUse, command, chname)
-		} else if histType != history.Tagmsg {
-			session.sendSplitMsgFromClientInternal(false, details.nickMask, details.accountName, tagsToUse, command, chname, message)
-		}
-	}
+	rb.addEchoMessage(details, command, message, clientOnlyTags, chname)
 
 	for _, member := range channel.Members() {
-		// echo-message is handled above, so skip sending the msg to the user themselves as well
-		if member == client {
-			continue
-		}
 		if minPrefixMode != modes.Mode(0) && !channel.ClientIsAtLeast(member, minPrefixMode) {
 			// STATUSMSG
 			continue
 		}
 
 		for _, session := range member.Sessions() {
+			if session == rb.session {
+				continue // we already sent echo-message, if applicable
+			}
+
 			if isCTCP && session.isTor {
 				continue // #753
 			}
diff --git a/irc/handlers.go b/irc/handlers.go
index 48391eb8..c31a7e75 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -2041,18 +2041,16 @@ func dispatchMessageToTarget(client *Client, tags map[string]string, histType hi
 		service, isService := OragonoServices[lowercaseTarget]
 		_, isZNC := zncHandlers[lowercaseTarget]
 
-		if histType == history.Privmsg {
+		if isService || isZNC {
+			rb.addEchoMessage(client.Details(), command, message, tags, target)
+			if histType != history.Privmsg {
+				return // NOTICE and TAGMSG to services are ignored
+			}
 			if isService {
 				servicePrivmsgHandler(service, server, client, message.Message, rb)
-				return
 			} else if isZNC {
 				zncPrivmsgHandler(client, lowercaseTarget, message.Message, rb)
-				return
 			}
-		}
-
-		// NOTICE and TAGMSG to services are ignored
-		if isService || isZNC {
 			return
 		}
 
@@ -2110,18 +2108,7 @@ func dispatchMessageToTarget(client *Client, tags map[string]string, histType hi
 		}
 
 		// the originating session may get an echo message:
-		if rb.session.capabilities.Has(caps.EchoMessage) {
-			hasTagsCap := rb.session.capabilities.Has(caps.MessageTags)
-			if histType == history.Tagmsg && hasTagsCap {
-				rb.AddFromClient(message.Time, message.Msgid, nickMaskString, accountName, tags, command, tnick)
-			} else {
-				tagsToSend := tags
-				if !hasTagsCap {
-					tagsToSend = nil
-				}
-				rb.AddSplitMessageFromClient(nickMaskString, accountName, tagsToSend, command, tnick, message)
-			}
-		}
+		rb.addEchoMessage(details, command, message, tags, tnick)
 		if histType != history.Notice {
 			//TODO(dan): possibly implement cooldown of away notifications to users
 			if away, awayMessage := user.Away(); away {
diff --git a/irc/responsebuffer.go b/irc/responsebuffer.go
index 4dde2050..8eb5bdde 100644
--- a/irc/responsebuffer.go
+++ b/irc/responsebuffer.go
@@ -143,6 +143,23 @@ func (rb *ResponseBuffer) AddSplitMessageFromClient(fromNickMask string, fromAcc
 	}
 }
 
+func (rb *ResponseBuffer) addEchoMessage(details ClientDetails, command string, message utils.SplitMessage, tags map[string]string, target string) {
+	if rb.session.capabilities.Has(caps.EchoMessage) {
+		hasTagsCap := rb.session.capabilities.Has(caps.MessageTags)
+		if command == "TAGMSG" {
+			if hasTagsCap {
+				rb.AddFromClient(message.Time, message.Msgid, details.nickMask, details.accountName, tags, command, target)
+			}
+		} else {
+			tagsToSend := tags
+			if !hasTagsCap {
+				tagsToSend = nil
+			}
+			rb.AddSplitMessageFromClient(details.nickMask, details.accountName, tagsToSend, command, target, message)
+		}
+	}
+}
+
 func (rb *ResponseBuffer) sendBatchStart(blocking bool) {
 	if rb.batchID != "" {
 		// batch already initialized