27c8056885 rpc: Disallow gettxoutsetinfo queries for a specific block with use_index=false (Martin Zumsande)
Pull request description:
In the `gettxoutsetinfo` RPC, if we set `use_index` to false but specify `hash_or_height`, we currently hit a nonfatal error, e.g. `gettxoutsetinfo "muhash" "1" "false"` results in:
```
Internal bug detected: "!pindex || pindex->GetBlockHash() == view->GetBestBlock()"
rpc/blockchain.cpp:836 (GetUTXOStats)
```
The failing check was added in [#24410](664a14ba7c), but the previous behavior, returning the specified height together with data corresponding to the tip's height, was very confusing too in my opinion.
Fix this by disallowing the interaction of `use_index=false` and `hash_or_height` and add a RPC help example with `-named` because users might ask themselves how to use the `use_index` flag witout hitting an error.
An alternative way would be to allow the interaction if the specified `hash_or_height` happens to correspond to the tip (which should then also be applied to the `HASH_SERIALIZED` check before). If reviewers would prefer that, please say so.
ACKs for top commit:
fjahr:
utACK 27c8056885
shaavan:
ACK 27c8056885
Tree-SHA512: 1d81c34eaa48c86134a2cf7193246d5de6bfd819d413c3b3fae9cb9290e0297a336111eeaecede2f0f020b0f9a181d240de0da4493e1b387fe63b8189154442b