Can't send orphan transactions with rpc #10562

I'm trying to push this transaction:

bitcoin-cli sendrawtransaction 0100000001bf9d8ca2bd060340c320c82432c57d53239d3e8d64c97dd302bb77b6b1ea779e010000006a4730440220628092918b8860dd21e2c89e082a096c38a723ae257f8ed011963121f54ff4e6022065480f3f9c265a3984e02e899d6c4494bf6de971032e196eeedd594593455ce5012102962425f1a1e9d8e372a85215bacfce533c6178bfd8e6c8dc7dcb79042daf2b99ffffffff02d9cd0300000000001976a914000f8b63ccf18b719537b5d5e10062f61239fd1288acb9e41100000000001976a914266bf5dc7d008ca5e1cb650b233e33a85143bb7c88ac00000000

Which returns

error code: -25
error message:
Missing inputs

But I also can't send the missing input it complains about:

bitcoin-cli sendrawtransaction 010000000119cf20c58a66a05020cc0eae50283cc3c2240c236dca8628f08d0bd9122fbc3f010000006b483045022100df4237d0a7bdbe5a08d708d735c70f4e9944c30ee343878dc29b96b32203ee4c0220462ef4837c38c8b49fa3b4bc827b3d7ea4c277f2089a6f68ff126b97af8d54f20121034f51458629ade2f2291fb38c7f06958ae313a1a43755c80a24513b1c9ab34015ffffffff02e3450a00000000001976a914a18adb0d09a1e46f174b421c6b9aa2496f7aa40688ac6abb1600000000001976a914c5ea832db560cef4b400356527b483609e9b1e4e88ac00000000

which returns

error code: -26
error message:
66: insufficient priority

So it's a bit of a catch-22. I would expect the first one to work (it pays a lot of fees), and add the transaction to the orphan transactions or something. Also the error message format is a bit inconsistent.

(and if anyone is feeling kind, propagating those transactions would be appreciated)

Just some notes:

• The concept that transaction pay with solely their coin age (aka. priority) will be removed in 0.15.0
• Even though the documentation for prioritisetransaction implies it is only meant for miners, you can use it to force your tx into the mempool.
• Alternatively, (on 0.15.0 and later) you could restart the node with -minrelaytxfee=0 and then get that transaction into your mempool.

Though, none of those guarantee that your tx will be accepted by other nodes or miners.

It's been a while since I've looked at the code, so I might be off the mark: but I believe when the client receives a transaction with unknown parents it's put into an "orphan pool", and it can later move into the mempool when the unknown parents are seen.

So I think the same behavior should happen with sendrawtransaction, that the transaction gets added to your orphan pool and sent out to your peers. Then you can add the other transaction, and push it out to your peers too.

Sending peers transactions which do not have sufficient fee to not be size-limited out of the mempool does not put those transactions in the orphan map and, thus, in order to properly relay transactions which are CPFP'd you need to broadcast them in reverse-dependency order (and hope your peer's orphan map is sufficiently large). Indeed, having a similar concept for sendrawtransaction (or, really, the ability to send multiple transactions with one call) would be nice, but we probably need to fix the relay behavior (both from-sendrawtransaction and from-peers) to support it as well to make sure we dont accept transactions and then not succeed in relaying them anywhere.