message: When validating DSP, return Invalid if P2SH is true or GetOp fails
  Other validation such as checking the pubkey are done in VerifyScript
  using the DSPSignatureChecker.
diff: @@ -257,12 +257,16 @@ DoubleSpendProof::Validity DoubleSpendProof::validate(const CTxMemPool &pool, co
  if (tx.vin[i].prevout.n == (size_t)m_prevOutIndex && tx.vin[i].prevout.hash == m_prevTxId)
  {
  // Found the input script we need!
  -
  CScript inScript = tx.vin[i].scriptSig;
  + if (inScript.IsPayToScriptHash())
  + return Invalid;
  +
  auto scriptIter = inScript.begin();
  opcodetype type;
  - inScript.GetOp(scriptIter, type); // P2PKH: first signature
  - inScript.GetOp(scriptIter, type, pubkey); // then pubkey
  + if (!inScript.GetOp(scriptIter, type)) // P2PKH: first signature
  + return Invalid;
  + if (!inScript.GetOp(scriptIter, type, pubkey)) // then pubkey
  + return Invalid;
  break;
  }
  }
  