From 12577c10bb5af7f21cc234e918fb668ea318115b Mon Sep 17 00:00:00 2001
From: delthas <delthas@dille.cc>
Date: Mon, 11 Apr 2022 17:20:51 +0200
Subject: [PATCH] upstream: handle CAP ACK -name

We'll need this for echo-message.
---
 upstream.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/upstream.go b/upstream.go
index 37dfd9f..cbb9af6 100644
--- a/upstream.go
+++ b/upstream.go
@@ -543,7 +543,12 @@ func (uc *upstreamConn) handleMessage(ctx context.Context, msg *irc.Message) err
 			caps := strings.Fields(subParams[0])
 
 			for _, name := range caps {
-				if err := uc.handleCapAck(ctx, strings.ToLower(name), subCmd == "ACK"); err != nil {
+				enable := subCmd == "ACK"
+				if strings.HasPrefix(name, "-") {
+					name = strings.TrimPrefix(name, "-")
+					enable = false
+				}
+				if err := uc.handleCapAck(ctx, strings.ToLower(name), enable); err != nil {
 					return err
 				}
 			}