`lighting-cli decode` fails to decode rune

[nepet]

It seems that lightnig-cli decode ignores or strips the == padding chars off an encoded rune and fails to decode it.

Failing example with padding chars:

 lightning-cli --regtest decode "zFMd1fjhrAYxUeFA54TjloZqOt8JrA_i_nYwIgXkag49MA=="
{
   "code": -32602,
   "message": "unknown parameter: zFMd1fjhrAYxUeFA54TjloZqOt8JrA_i_nYwIgXkag49MA, this may be caused by a failure to autodetect key=value-style parameters. Please try using the -k flag and explicit key=value pairs of parameters."
}

Working example, without padding chars:

 lightning-cli --regtest decode "_RWaZZRI7wAYU2hqlFBmYgC_dFczcpAdI_9O87YbDpg9MCZtZXRob2RebGlzdHxtZXRob2ReZ2V0fG1ldGhvZD1zdW1tYXJ5Jm1ldGhvZC9saXN0ZGF0YXN0b3Jl"
{
   "type": "rune",
   "unique_id": "0",
   "string": "fd159a659448ef001853686a9450666200bf74573372901d23ff4ef3b61b0e98:=0&method^list|method^get|method=summary&method/listdatastore",
   "restrictions": [
      {
         "alternatives": [
            "method^list",
            "method^get",
            "method=summary"
         ],
         "summary": "method (of command) starts with 'list' OR method (of command) starts with 'get' OR method (of command) equal to 'summary'"
      },
      {
         "alternatives": [
            "method/listdatastore"
         ],
         "summary": "method (of command) unequal to 'listdatastore'"
      }
   ],
   "valid": true
}

Both runes are from the example in the createrune doc.

[rustyrussell]

Yeah, the heuristic that decides whether to use named or positional parameters is naive: it sees the = and thinks that you are specifying a parameter name. Use -o to force it into ordered mode, or use the parameter name: lightning-cli --regtest decode string="zFMd1fjhrAYxUeFA54TjloZqOt8JrA_i_nYwIgXkag49MA=="