why the aleth can run the odd length of bytecode?Is it a bug?

[BattleBird]

Parity Ethereum version: the newest one
Operating system: Linux(ubuntu16.04)
Installation: built from source
Fully synchronized: no

Aleth Ethereum version: the newest one
Operating system: Linux(ubuntu16.04)
Installation: built from source
Fully synchronized: no

steps to reproduce
import subprocess

retcodealethout = subprocess.call(
"./parity-evm stats --json --code " + "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"

• " --input " + "06fdde03",timeout=60,shell=True)
  print(retcodealethout)
  retcodealethtrace = subprocess.call(
  "./benchmarkEVMs/aleth-vm trace --code " + "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"
  • " --mnemonics --input " + "06fdde03" + " > " + "./" + "aletraceout 2>&1",timeout=60,shell=True)
    print(retcodealethtrace)
    actual behavior

The parity-vm' output: Invalid --code: Invalid input length

The aleth-vm'output:

[
{
"depth" : "0",
"gas" : "9223372036854775807",
"gasCost" : "0",
"memory" : [],
"op" : "MOD",
"pc" : "0",
"stack" : [],
"storage" : {}
}
]

Why there exits different behaviours between parity and aleth-vm. Why the aleth-vm don't refuse the odd length of bytecode. I think it may introduce some bugs using crafted bytecode.

[chfast]

It's a matter of converting hex to binary. There exist different variants of this in Aleth. I suspect that in this case in pads the first byte with zero. E.g. "abc" becomes "0abc".