fix #4026

lib/synchronizer.py

@@ -84,6 +84,8 @@ class Synchronizer(ThreadJob):
         return bh2u(hashlib.sha256(status.encode('ascii')).digest())
 
     def on_address_status(self, response):
+        if self.wallet.synchronizer is None:
+            return  # we have been killed, this was just an orphan callback
         params, result = self.parse_response(response)
         if not params:
             return
@@ -98,6 +100,8 @@ class Synchronizer(ThreadJob):
             self.requested_addrs.remove(addr)
 
     def on_address_history(self, response):
+        if self.wallet.synchronizer is None:
+            return  # we have been killed, this was just an orphan callback
         params, result = self.parse_response(response)
         if not params:
             return
@@ -127,6 +131,8 @@ class Synchronizer(ThreadJob):
         self.requested_histories.pop(addr)
 
     def tx_response(self, response):
+        if self.wallet.synchronizer is None:
+            return  # we have been killed, this was just an orphan callback
         params, result = self.parse_response(response)
         if not params:
             return

lib/verifier.py

@@ -65,6 +65,8 @@ class SPV(ThreadJob):
             self.undo_verifications()
 
     def verify_merkle(self, r):
+        if self.wallet.verifier is None:
+            return  # we have been killed, this was just an orphan callback
         if r.get('error'):
             self.print_error('received an error:', r)
             return
@@ -95,7 +97,8 @@ class SPV(ThreadJob):
         self.print_error("verified %s" % tx_hash)
         self.wallet.add_verified_tx(tx_hash, (tx_height, header.get('timestamp'), pos))
 
-    def hash_merkle_root(self, merkle_s, target_hash, pos):
+    @classmethod
+    def hash_merkle_root(cls, merkle_s, target_hash, pos):
         h = hash_decode(target_hash)
         for i in range(len(merkle_s)):
             item = merkle_s[i]

lib/wallet.py

@@ -912,7 +912,8 @@ class Abstract_Wallet(PrintError):
                     # make tx local
                     self.unverified_tx.pop(tx_hash, None)
                     self.verified_tx.pop(tx_hash, None)
-                    self.verifier.merkle_roots.pop(tx_hash, None)
+                    if self.verifier:
+                        self.verifier.merkle_roots.pop(tx_hash, None)
                     # but remove completely if not is_mine
                     if self.txi[tx_hash] == {}:
                         # FIXME the test here should be for "not all is_mine"; cannot detect conflict in some cases