From 5ac7ea5b1c83b87e33b4c35cd26d15e1889a3ffd Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Mon, 27 May 2019 14:33:59 -0400
Subject: [PATCH] fix data race on exitedSnomaskSent

---
 irc/client.go   | 3 ++-
 irc/getters.go  | 6 ++++++
 irc/handlers.go | 6 +++---
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/irc/client.go b/irc/client.go
index c31bdd28..add5b3d4 100644
--- a/irc/client.go
+++ b/irc/client.go
@@ -987,6 +987,7 @@ func (client *Client) destroy(session *Session) {
 		// if it's our job to destroy it, don't let anyone else try
 		client.destroyed = true
 	}
+	exitedSnomaskSent := client.exitedSnomaskSent
 	client.stateMutex.Unlock()
 
 	// destroy all applicable sessions:
@@ -1101,7 +1102,7 @@ func (client *Client) destroy(session *Session) {
 		friend.sendFromClientInternal(false, splitQuitMessage.Time, splitQuitMessage.Msgid, details.nickMask, details.accountName, nil, "QUIT", quitMessage)
 	}
 
-	if !client.exitedSnomaskSent && registered {
+	if !exitedSnomaskSent && registered {
 		client.server.snomasks.Send(sno.LocalQuits, fmt.Sprintf(ircfmt.Unescape("%s$r exited the network"), details.nick))
 	}
 }
diff --git a/irc/getters.go b/irc/getters.go
index 4d3ad7a8..91187cc1 100644
--- a/irc/getters.go
+++ b/irc/getters.go
@@ -187,6 +187,12 @@ func (client *Client) SetAway(away bool, awayMessage string) (changed bool) {
 	return
 }
 
+func (client *Client) SetExitedSnomaskSent() {
+	client.stateMutex.Lock()
+	client.exitedSnomaskSent = true
+	client.stateMutex.Unlock()
+}
+
 // uniqueIdentifiers returns the strings for which the server enforces per-client
 // uniqueness/ownership; no two clients can have colliding casefolded nicks or
 // skeletons.
diff --git a/irc/handlers.go b/irc/handlers.go
index a80c366a..e6cf61ce 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -1052,7 +1052,7 @@ func dlineHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Res
 		}
 
 		for _, mcl := range clientsToKill {
-			mcl.exitedSnomaskSent = true
+			mcl.SetExitedSnomaskSent()
 			mcl.Quit(fmt.Sprintf(mcl.t("You have been banned from this server (%s)"), reason), nil)
 			if mcl == client {
 				killClient = true
@@ -1362,7 +1362,7 @@ func killHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Resp
 	quitMsg := fmt.Sprintf("Killed (%s (%s))", client.nick, comment)
 
 	server.snomasks.Send(sno.LocalKills, fmt.Sprintf(ircfmt.Unescape("%s$r was killed by %s $c[grey][$r%s$c[grey]]"), target.nick, client.nick, comment))
-	target.exitedSnomaskSent = true
+	target.SetExitedSnomaskSent()
 
 	target.Quit(quitMsg, nil)
 	target.destroy(nil)
@@ -1489,7 +1489,7 @@ func klineHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Res
 		}
 
 		for _, mcl := range clientsToKill {
-			mcl.exitedSnomaskSent = true
+			mcl.SetExitedSnomaskSent()
 			mcl.Quit(fmt.Sprintf(mcl.t("You have been banned from this server (%s)"), reason), nil)
 			if mcl == client {
 				killClient = true