Refactor DigestItem (#2108)

* Add `start_aura2`.

* .gitignore patch conflict files

and remove one that accidentally got committed

* Fix build

The tests still don’t work.

* Fix compilation errors

* Fix compile errors (again)

* Try (and fail) to fix tests

* Properly deserialize data

Previously, `DigestItem::Consensus` had no separate `DigestItemType`,
so it did not get properly serialized and deserialized.

* Add extra debug logging.  Always allow old seals.

A `RUST_LOG=substrate_aura_consensus cargo test --all -- --nocapture \
tests::authoring_blocks` revealed that old seals were being and
rejected, causing the test to hang.  As a temporary debug measure, allow
old seals unconditionally, so that CI can test if this fixes the
problem.

* Forcibly disable rejection of old seals

* Use old trait, but newer serialization

The old trait for `CompatibleDigestItem` actually worked.  By changing
its implementation, one can ensure that all *new* seals have the modern
form, but *legacy* seals are still decoded correctly.

* Bump impl version

* Squash spurious deprecation warning

`rustc` should not be emitting a deprecation warning in deprecated
code, but it does, so silence it.

* Rip out unused Cargo feature

* Move AURA to aura_primitives

* Respond to code review

* Wrap overly-long line

* Reduce logging verbosity and add target

* Add dependency on `sr-primitives` to `aura_primitives`

* Fix build

It failed with a message about Cargo.lock being out of date.

* core: aura: rename aura engine id const

* core: aura: remove superfluous logging

* core: primitives: add removed semicolons

* core: aura: remove unused import

* core: network: style fix

* runtime: update wasm blobs

* runtime: bump impl_version

* core: primitives: tag all DigestItemType variants explicitly

substrate/node/cli/src/service.rs

@@ -148,6 +148,7 @@ construct_service_factory! {
 					client,
 					NothingExtra,
 					config.custom.inherent_data_providers.clone(),
+					true,
 				).map_err(Into::into)
 			}},
 		LightImportQueue = AuraImportQueue<Self::Block>
@@ -159,6 +160,7 @@ construct_service_factory! {
 					client,
 					NothingExtra,
 					config.custom.inherent_data_providers.clone(),
+					true,
 				).map_err(Into::into)
 			}
 		},

substrate/node/runtime/src/lib.rs

@@ -58,8 +58,8 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("node"),
 	impl_name: create_runtime_str!("substrate-node"),
 	authoring_version: 10,
-	spec_version: 48,
-	impl_version: 49,
+	spec_version: 49,
+	impl_version: 50,
 	apis: RUNTIME_API_VERSIONS,
 };
 

substrate/node/runtime/wasm/Cargo.lock

@@ -2589,6 +2589,7 @@ dependencies = [
 name = "substrate-consensus-aura-primitives"
 version = "0.1.0"
 dependencies = [
+ "sr-primitives 0.1.0",
  "substrate-client 0.1.0",
 ]