sanity check read_header

8 years ago · 882e259a78
1 changed files with 2 additions and 0 deletions
--- a/lib/blockchain.py
+++ b/lib/blockchain.py
@ -242,6 +242,8 @@ class Blockchain(util.PrintError):

    def read_header(self, height):
        assert self.parent_id != self.checkpoint
+        if height < 0:
+            return
        if height < self.checkpoint:
            return self.parent().read_header(height)
        if height > self.height():