fix #3635

lib/blockchain.py

@@ -181,7 +181,7 @@ class Blockchain(util.PrintError):
         if d < 0:
             chunk = chunk[-d:]
             d = 0
-        self.write(chunk, d)
+        self.write(chunk, d, index > len(self.checkpoints))
         self.swap_with_parent()
 
     def swap_with_parent(self):
@@ -218,11 +218,11 @@ class Blockchain(util.PrintError):
         blockchains[self.checkpoint] = self
         blockchains[parent.checkpoint] = parent
 
-    def write(self, data, offset):
+    def write(self, data, offset, truncate=True):
         filename = self.path()
         with self.lock:
             with open(filename, 'rb+') as f:
-                if offset != self._size*80:
+                if truncate and offset != self._size*80:
                     f.seek(offset)
                     f.truncate()
                 f.seek(offset)
@@ -263,7 +263,7 @@ class Blockchain(util.PrintError):
         elif height == 0:
             return bitcoin.NetworkConstants.GENESIS
         elif height < len(self.checkpoints) * 2016:
-            assert (height+1) % 2016 == 0
+            assert (height+1) % 2016 == 0, height
             index = height // 2016
             h, t = self.checkpoints[index]
             return h

lib/network.py

@@ -218,6 +218,7 @@ class Network(util.DaemonThread):
         self.interfaces = {}
         self.auto_connect = self.config.get('auto_connect', True)
         self.connecting = set()
+        self.requested_chunks = set()
         self.socket_queue = queue.Queue()
         self.start_network(self.protocol, deserialize_proxy(self.config.get('proxy')))
 
@@ -754,11 +755,12 @@ class Network(util.DaemonThread):
             if self.config.is_fee_estimates_update_required():
                 self.request_fee_estimates()
 
-    def request_chunk(self, interface, idx):
-        interface.print_error("requesting chunk %d" % idx)
-        self.queue_request('blockchain.block.get_chunk', [idx], interface)
-        interface.request = idx
-        interface.req_time = time.time()
+    def request_chunk(self, interface, index):
+        if index in self.requested_chunks:
+            return
+        interface.print_error("requesting chunk %d" % index)
+        self.requested_chunks.add(index)
+        self.queue_request('blockchain.block.get_chunk', [index], interface)
 
     def on_get_chunk(self, interface, response):
         '''Handle receiving a chunk of block headers'''
@@ -768,19 +770,19 @@ class Network(util.DaemonThread):
         if result is None or params is None or error is not None:
             interface.print_error(error or 'bad response')
             return
-        # Ignore unsolicited chunks
         index = params[0]
-        if interface.request != index:
+        # Ignore unsolicited chunks
+        if index not in self.requested_chunks:
             return
+        self.requested_chunks.remove(index)
         connect = interface.blockchain.connect_chunk(index, result)
-        # If not finished, get the next chunk
         if not connect:
             self.connection_down(interface.server)
             return
+        # If not finished, get the next chunk
         if interface.blockchain.height() < interface.tip:
             self.request_chunk(interface, index+1)
         else:
-            interface.request = None
             interface.mode = 'default'
             interface.print_error('catch up done', interface.blockchain.height())
             interface.blockchain.catch_up = None

lib/verifier.py

@@ -34,7 +34,6 @@ class SPV(ThreadJob):
         # Keyed by tx hash.  Value is None if the merkle branch was
         # requested, and the merkle root once it has been verified
         self.merkle_roots = {}
-        self.requested_chunks = {}
 
     def run(self):
         lh = self.network.get_local_height()
@@ -43,15 +42,9 @@ class SPV(ThreadJob):
             # do not request merkle branch before headers are available
             if (tx_height > 0) and (tx_height <= lh):
                 header = self.network.blockchain().read_header(tx_height)
-                index = tx_height // 2016
-                #print(index, header)
-                if header is None:
-                    if index not in self.requested_chunks  and self.network.interface:
-                        print("requesting chunk", index)
-                        #request = ('blockchain.block.get_chunk', [index])
-                        #self.network.send([request], self.verify_merkle)
-                        self.requested_chunks[index] = None
-                        self.network.request_chunk(self.network.interface, index)
+                if header is None and self.network.interface:
+                    index = tx_height // 2016
+                    self.network.request_chunk(self.network.interface, index)
                 else:
                     if tx_hash not in self.merkle_roots:
                         request = ('blockchain.transaction.get_merkle',