FTPS connection silently dies after idle timeout — status still shows "connected", no auto-reconnect (FTP/FTPS missing keepalive & socket event listeners) #8

Environment

• Extension version: 1.2.21

• Protocol: FTPS (explicit TLS, port 21)

• OS: Windows 11

• Editor: Trae (VSCode-based, vscode engine ^1.75)

Steps to Reproduce

1. Connect to an FTPS server (protocol: "ftps", port 21) via .vscode/sftp.json.

2. Upload/download works fine right after connecting.

3. Leave the connection idle for a few minutes to tens of minutes.

4. Try to upload or download again.

Actual Behavior

• All uploads/downloads fail, but the status bar / explorer still shows the connection as "connected".

• The only workaround is manually disconnecting and reconnecting.

• Plain FTP and SFTP do NOT have this problem — both survive idle periods correctly.

Expected Behavior

• Either the idle control connection is kept alive (NOOP), or the dead connection is detected and auto-reconnected (the stackerftp.autoReconnect: true setting already exists but never fires for FTP/FTPS).

Root Cause Analysis (from bundled dist/extension.js 1.2.21)

Comparing the two connection classes:

1. SFTPConnection attaches listeners to the ssh2 client (close / end / error), sets _connected = false and emits "disconnected" on drop — which triggers ConnectionManager.scheduleReconnect() (autoReconnect defaults to true). That's why SFTP works.

2. FTPConnection sets _connected = true in connect() and never attaches any listener to the control socket (client.ftp.socket), and **never emits "disconnected"