add + clarify comments (#495)

protocol/app/ante.go

@@ -74,13 +74,18 @@ func newAnteDecoratorChain(options HandlerOptions) []sdk.AnteDecorator {
 				ante.NewSetUpContextDecorator(), // outermost AnteDecorator. SetUpContext must be called first
 			),
 		),
+
 		// Set `FreeInfiniteGasMeter` for app-injected messages, and clob transactions.
 		customante.NewFreeInfiniteGasDecorator(),
+
 		ante.NewExtensionOptionsDecorator(options.ExtensionOptionChecker),
 		customante.NewValidateMsgTypeDecorator(),
+
+		// Note: app-injected messages are not signed on purpose.
 		libante.NewAppInjectedMsgAnteWrapper(
 			ante.NewValidateBasicDecorator(),
 		),
+
 		ante.NewTxTimeoutHeightDecorator(),
 		ante.NewValidateMemoDecorator(options.AccountKeeper),
 		ante.NewConsumeGasForTxSizeDecorator(options.AccountKeeper),
@@ -98,21 +103,30 @@ func newAnteDecoratorChain(options HandlerOptions) []sdk.AnteDecorator {
 		),
 
 		// SetPubKeyDecorator must be called before all signature verification decorators
+		// Note: app-injected messages are not signed on purpose.
 		libante.NewAppInjectedMsgAnteWrapper(
 			ante.NewSetPubKeyDecorator(options.AccountKeeper),
 		),
+
 		ante.NewValidateSigCountDecorator(options.AccountKeeper),
+
+		// Note: app-injected messages don't require Gas fees.
 		libante.NewAppInjectedMsgAnteWrapper(
 			ante.NewSigGasConsumeDecorator(options.AccountKeeper, options.SigGasConsumer),
 		),
+
+		// Note: app-injected messages are not signed on purpose.
 		libante.NewAppInjectedMsgAnteWrapper(
 			customante.NewSigVerificationDecorator(options.AccountKeeper, options.SignModeHandler),
 		),
+
+		// Note: app-injected messages, and short-term clob txs don't have sequence numbers on purpose.
 		libante.NewAppInjectedMsgAnteWrapper(
 			clobante.NewShortTermSingleMsgClobTxAnteWrapper(
 				ante.NewIncrementSequenceDecorator(options.AccountKeeper),
 			),
 		),
+
 		clobante.NewRateLimitDecorator(options.ClobKeeper),
 		clobante.NewClobDecorator(options.ClobKeeper),
 	}

protocol/lib/ante/app_injected_msg_ante_wrapper.go

@@ -27,9 +27,10 @@ func (imaw AppInjectedMsgAnteWrapper) AnteHandle(
 	simulate bool,
 	next sdk.AnteHandler,
 ) (sdk.Context, error) {
-	// "App-injected message" tx is skipped, because such tx is not signed on purpose.
-	// If a tx is not signed, signature related functions like `GetSigners` will fail
-	// with "empty address string is not allowed" error.
+	// "App-injected message" tx must skip certain AnteHandlers.
+	// For example, "App-injected message" tx is not signed on purpose and if a tx is not signed,
+	// signature related functions like `GetSigners` will fail due to signer field being empty.
+	// Therefore, we skip the AnteHandlers that require the tx to be signed.
 	if IsSingleAppInjectedMsg(tx.GetMsgs()) {
 		return next(ctx, tx, simulate)
 	}