ABCI calls should crash/exit in all cases when the call itself report…

…s and error (backport cometbft#496) (cometbft#519)

* ABCI calls should crash/exit in all cases when the call itself reports and error (cometbft#496)

* Review call hierarchies of ABCI methods to make sure they panic on error

* Added changelog

* Trying 1.20.2 explicitly

(cherry picked from commit 2ab8598)

# Conflicts:
#	.changelog/v0.37.0/bug-fixes/496-error-on-applyblock-should-panic.md

* Revert "ABCI calls should crash/exit in all cases when the call itself reports and error (cometbft#496)"

This reverts commit 825ac9e.

* [cherry-picked] ABCI calls should crash/exit in all cases when the call itself reports and error (cometbft#496)

* Review call hierarchies of ABCI methods to make sure they panic on error

* Added changelog

* Trying 1.20.2 explicitly

---------

Co-authored-by: Sergio Mena <sergio@informal.systems>

.changelog/unreleased/bug-fixes/496-error-on-applyblock-should-panic.md

@@ -0,0 +1,2 @@
+- `[consensus]` Unexpected error conditions in `ApplyBlock` are non-recoverable, so ignoring the error and carrying on is a bug. We replaced a `return` that disregarded the error by a `panic`.
+  ([\#496](https://github.com/cometbft/cometbft/pull/496))

consensus/state.go

@@ -1706,8 +1706,7 @@ func (cs *State) finalizeCommit(height int64) {
 		block,
 	)
 	if err != nil {
-		logger.Error("failed to apply block", "err", err)
-		return
+		panic(fmt.Sprintf("failed to apply block; error %v", err))
 	}
 
 	fail.Fail() // XXX

state/execution.go

@@ -158,7 +158,7 @@ func (blockExec *BlockExecutor) ProcessProposal(
 		NextValidatorsHash: block.NextValidatorsHash,
 	})
 	if err != nil {
-		return false, ErrInvalidBlock(err)
+		return false, err
 	}
 	if resp.IsStatusUnknown() {
 		panic(fmt.Sprintf("ProcessProposal responded with status %s", resp.Status.String()))