From 35b09f069c85ffc9165e3cc8b572dda77ae908f6 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Mon, 14 Mar 2022 19:30:29 +0100
Subject: [PATCH] downstream: atomically ack/nak capabilities

---
 downstream.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/downstream.go b/downstream.go
index 09262d9..e2dfe6b 100644
--- a/downstream.go
+++ b/downstream.go
@@ -875,9 +875,9 @@ func (dc *downstreamConn) handleCapCommand(cmd string, args []string) error {
 			}}
 		}
 
-		// TODO: atomically ack/nak the whole capability set
 		caps := strings.Fields(args[0])
 		ack := true
+		m := make(map[string]bool, len(caps))
 		for _, name := range caps {
 			name = strings.ToLower(name)
 			enable := !strings.HasPrefix(name, "-")
@@ -900,7 +900,14 @@ func (dc *downstreamConn) handleCapCommand(cmd string, args []string) error {
 				break
 			}
 
-			dc.caps.SetEnabled(name, enable)
+			m[name] = enable
+		}
+
+		// Atomically ack the whole capability set
+		if ack {
+			for name, enable := range m {
+				dc.caps.SetEnabled(name, enable)
+			}
 		}
 
 		reply := "NAK"