Miniscript support for decodescript #25606

Current behavior:

src/bitcoin-cli -signet decodescript 2103d3b9c8cc852f3b4a06bad1711fd1a1761a592bf1475edc0a5f97b31759eba330ac736476a914b6e87320e876a740fc1365aeb1f4b6ab2fe4210b88ad53b268

{
  "asm": "03d3b9c8cc852f3b4a06bad1711fd1a1761a592bf1475edc0a5f97b31759eba330 OP_CHECKSIG OP_IFDUP OP_NOTIF OP_DUP OP_HASH160 b6e87320e876a740fc1365aeb1f4b6ab2fe4210b OP_EQUALVERIFY OP_CHECKSIGVERIFY 3 OP_CHECKSEQUENCEVERIFY OP_ENDIF",
  "desc": "raw(2103d3b9c8cc852f3b4a06bad1711fd1a1761a592bf1475edc0a5f97b31759eba330ac736476a914b6e87320e876a740fc1365aeb1f4b6ab2fe4210b88ad53b268)#uul8nd2t",
  "type": "nonstandard",
  "p2sh": "2N62ryy2gBC2QBSdsm832Tv6qCW5py53wJn",
  "segwit": {
    "asm": "0 43c1d0387e91045591f19ff6d60af2bc0d91473b79dc3238aa9d0430f89741bc",
    "desc": "addr(tb1qg0qaqwr7jyz9ty03nlmdvzhjhsxez3em08wryw92n5zrp7yhgx7qj56vra)#ugngfnm5",
    "hex": "002043c1d0387e91045591f19ff6d60af2bc0d91473b79dc3238aa9d0430f89741bc",
    "address": "tb1qg0qaqwr7jyz9ty03nlmdvzhjhsxez3em08wryw92n5zrp7yhgx7qj56vra",
    "type": "witness_v0_scripthash",
    "p2sh-segwit": "2N9diLEHbASsz1oAeDQJPg5mb4LaAju9175"
  }
}

It would be nice if this (also) returned miniscript.

Perhaps getaddressinfo could do this as well (after #24148).

cc @sipa, @darosior

After #24148 i think it should be the default behaviour to show a Miniscript descriptor (for the "desc" field) if one could be parsed: InferDescriptor would try parsing a Miniscript under P2WSH context (as in your example). EDIT: InferDescriptor is using a dummy sig provider so it wouldn't work, see #27007 (comment).

However, note your Script here would not be parsed because the Miniscript parser is not passed the preimage to the key hash for OP_DUP OP_HASH160 b6e87320e876a740fc1365aeb1f4b6ab2fe4210b OP_EQUALVERIFY OP_CHECKSIGVERIFY. So i'd say it's the best we can reasonably do.

hmm seems I opened up a mostly similar issue in https://github.com/bitcoin/bitcoin/issues/27007