lightningd: only allow closing to native segwit

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Removed: JSON-RPC: `close` `destination` no longer allows p2pkh or p2sh addresses (deprecated v0.11.0)

common/shutdown_scriptpubkey.c

@@ -48,9 +48,9 @@ static bool is_valid_witnessprog(const u8 *scriptpubkey)
 
 bool valid_shutdown_scriptpubkey(const u8 *scriptpubkey,
 				 bool anysegwit,
-				 bool anchors)
+				 bool allow_oldstyle)
 {
-	if (!anchors) {
+	if (allow_oldstyle) {
 		if (is_p2pkh(scriptpubkey, NULL)
 		    || is_p2sh(scriptpubkey, NULL))
 			return true;

common/shutdown_scriptpubkey.h

@@ -16,8 +16,11 @@
  *  - if the `scriptpubkey` is not in one of the above forms:
  *    - SHOULD send a `warning`
  */
+
+/* We still allow them to specify an old-style P2PKH or P2SH (though we
+ * never will send such a thing!) if they're not using anchors. */
 bool valid_shutdown_scriptpubkey(const u8 *scriptpubkey,
 				 bool anysegwit,
-				 bool anchors);
+				 bool allow_oldstyle);
 
 #endif /* LIGHTNING_COMMON_SHUTDOWN_SCRIPTPUBKEY_H */