walletapi: sync_loop never exits on wallet close ("break" exits the select, not the for loop)

[Dirtybird99]

Summary

Wallet_Memory.sync_loop is intended to stop when the wallet closes, but its quit check uses break inside a select — which exits the select, not the enclosing for. The sync loop therefore never terminates.

derohe/walletapi/daemon_communication.go

Lines 183 to 191 in 6f9bd2c

	func (w *Wallet_Memory) sync_loop() {
	//logger = globals.Logger
	for {
	select {
	case <-w.Quit:
	break
	default:
	}

func (w *Wallet_Memory) sync_loop() {
	for {
		select {
		case <-w.Quit:
			break        // <-- exits the select, NOT the for loop
		default:
		}

Impact

After Close_Encrypted_Wallet() (which only sleeps 1s "to give goroutines some time to quit", walletapi/wallet_disk.go:149-150), the sync loop keeps running: it continues polling the daemon every timeout seconds and keeps calling save_if_disk() against a wallet the caller believes is closed. Applications that close one wallet and open another accumulate leaked sync loops, duplicate RPC traffic, and concurrent writers against wallet files.

Fix

select {
case <-w.Quit:
	return
default:
}

(Any other long-running loops keyed on w.Quit are worth auditing for the same pattern.)

[Dirtybird99]

Moved to PR #30 (it edits the same sync_loop): #30 (comment) — closing in favor of the PR thread.