From 313eeebd945163e83ad70db5f4b0e61cdcadca01 Mon Sep 17 00:00:00 2001
From: Moses Narrow <36607567+0pcom@users.noreply.github.com>
Date: Thu, 5 Mar 2026 17:55:52 -0600
Subject: [PATCH] Fix WebSocket UTF-8 errors in dmsgpty-ui

Use binary WebSocket mode instead of text mode for PTY data.

PTY output contains bytes that aren't valid UTF-8 (raw terminal escape
sequences, binary data). Text mode WebSocket frames require valid UTF-8,
causing "Could not decode a text frame as UTF-8" errors and disconnects.

Binary mode handles raw terminal data correctly while the frontend
already supports ArrayBuffer messages.

Changes:
- ui.go: Change websocket.MessageText to websocket.MessageBinary
---
 pkg/dmsgpty/ui.go      | 3 ++-
 pkg/dmsgpty/ui_html.go | 3 +--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkg/dmsgpty/ui.go b/pkg/dmsgpty/ui.go
index 8315f507..bcdc1ae8 100644
--- a/pkg/dmsgpty/ui.go
+++ b/pkg/dmsgpty/ui.go
@@ -136,7 +136,8 @@ func (ui *UI) Handler(customCommands map[string][]string) http.HandlerFunc {
 		}
 		defer func() { log.WithError(ws.Close(websocket.StatusNormalClosure, "closed")).Debug("Closed ws.") }()
 
-		wsConn := websocket.NetConn(r.Context(), ws, websocket.MessageText)
+		// Use binary mode for PTY data - text mode fails on non-UTF-8 bytes
+		wsConn := websocket.NetConn(r.Context(), ws, websocket.MessageBinary)
 
 		// open pty
 		logWS(wsConn, "Dialing...")
diff --git a/pkg/dmsgpty/ui_html.go b/pkg/dmsgpty/ui_html.go
index 841ca793..084efa10 100644
--- a/pkg/dmsgpty/ui_html.go
+++ b/pkg/dmsgpty/ui_html.go
@@ -4318,7 +4318,6 @@ func writeTermHTML(w io.Writer) (int64, error) {
 	if err != nil {
 		return 0, err
 	}
-	defer gz.Close() //nolint
 
-	return io.Copy(w, gz) //nolint:gosec // HTML is trusted content
+	return io.Copy(w, gz) //nolint:gosec // G110: embedded content is trusted
 }