request headers chunk if we need more than 50 blocks

lib/verifier.py

@@ -66,11 +66,12 @@ class WalletVerifier(threading.Thread):
 
         while True:
             # request missing chunks
-            max_index = (self.height+1)/2016
             if not all_chunks and self.height and not requested_chunks:
-                for i in range(0, max_index + 1):
-                    # test if we can read the first header of the chunk
-                    if self.read_header(i*2016): continue
+
+                if self.local_height + 50 < self.height:
+                    min_index = (self.local_height + 1)/2016
+                    max_index = (self.height + 1)/2016
+                    for i in range(min_index, max_index + 1):
                         # print "requesting chunk", i
                         self.interface.send([ ('blockchain.block.get_chunk',[i])], 'verifier')
                         requested_chunks.append(i)