IndexError: string index out of range doing catch_up about bitcoin-abe

[jabbervorx]

I still don't know anything about Python or Bitcoin internals, but, based on some comment from bitcoin talk I propose following fix:

--- deserialize.py~bak  2013-10-28 15:15:38.605861382 +0100
+++ deserialize.py      2013-10-28 15:17:35.241426261 +0100
@@ -244,14 +244,26 @@
     if opcode <= opcodes.OP_PUSHDATA4:
       nSize = opcode
       if opcode == opcodes.OP_PUSHDATA1:
-        nSize = ord(bytes[i])
-        i += 1
+        if i + 1 > len(bytes):
+          vch = "_INVALID_NULL"
+          i = len(bytes)
+        else:
+          nSize = ord(bytes[i])
+          i += 1
       elif opcode == opcodes.OP_PUSHDATA2:
-        (nSize,) = struct.unpack_from('<H', bytes, i)
-        i += 2
+        if i + 2 > len(bytes):
+          vch = "_INVALID_NULL"
+          i = len(bytes)
+        else:
+          (nSize,) = struct.unpack_from('<H', bytes, i)
+          i += 2
       elif opcode == opcodes.OP_PUSHDATA4:
-        (nSize,) = struct.unpack_from('<I', bytes, i)
-        i += 4
+        if i + 4 > len(bytes):
+          vch = "_INVALID_NULL"
+          i = len(bytes)
+        else:
+          (nSize,) = struct.unpack_from('<I', bytes, i)
+          i += 4
       if i+nSize > len(bytes):
         vch = "_INVALID_"+bytes[i:]
         i = len(bytes)

[dermoth]

Thanks. I don't have very strong knowledge of Bitcoin neither, but this patch looks OK. I'll make a pull request off it for now, while I let Abe load the remaining blocks with the patch applied. Once done i'll compare some stats and merge if all looks good.

Regards,

Thomas