Cannot properly parse block

[rllola]

What went wrong?

We are trying to use tendermint httpclient to query blocks. After a hardfork we are querying the new genesis block but have this error:

invalid block: last_commit is empty on non-first block

Steps to reproduce

• Run Namada indexer (https://github.com/Zondax/namadexer)
• Wait for hardfork block 237907 to fail

(If needed I can provide a minimal example)

Definition of "done"

Allowing parsing any kind of blocks regardless if they have empty commit or not.

[romac]

Right, looks like we have such checks here:

tendermint-rs/tendermint/src/block.rs

Lines 113 to 122 in f11a1be

	if last_commit.is_none() && header.height.value() != 1 {
	return Err(Error::invalid_block(
	"last_commit is empty on non-first block".to_string(),
	));
	}
	if last_commit.is_some() && header.height.value() == 1 {
	return Err(Error::invalid_block(
	"last_commit is filled on first block".to_string(),
	));
	}

Perhaps they should be bypassed when constructing a Block from an RPC response as we do not control the validity of the block we get in the response. But we should probably keep enforcing them when we build a Block by hand so to speak to still catch such mistakes when possible.

[romac]

I just opened a draft PR with a tentative fix.

If you add the following lines at the end of namadexer/Cargo.toml and build it again, does it solve the issue?

[patch.crates-io]
tendermint        = { git = "https://github.com/informalsystems/tendermint-rs.git", branch = "romac/allow-misformed-block" }
tendermint-rpc    = { git = "https://github.com/informalsystems/tendermint-rs.git", branch = "romac/allow-misformed-block" }
tendermint-proto  = { git = "https://github.com/informalsystems/tendermint-rs.git", branch = "romac/allow-misformed-block" }
tendermint-config = { git = "https://github.com/informalsystems/tendermint-rs.git", branch = "romac/allow-misformed-block" }

[rllola]

It is working! Awesome. I really didn't expect to have a solution so fast. 5 stars