handle returns correctly for transactional (#7301)

substrate/frame/support/procedural/src/transactional.rs

@@ -29,7 +29,7 @@ pub fn transactional(_attr: TokenStream, input: TokenStream) -> Result<TokenStre
 		#vis #sig {
 			use #crate_::storage::{with_transaction, TransactionOutcome};
 			with_transaction(|| {
-				let r = #block;
+				let r = (|| { #block })();
 				if r.is_ok() {
 					TransactionOutcome::Commit(r)
 				} else {

substrate/frame/support/test/tests/storage_transaction.rs

@@ -182,15 +182,20 @@ fn storage_transaction_commit_then_rollback() {
 
 #[test]
 fn transactional_annotation() {
+	fn set_value(v: u32) -> DispatchResult {
+		Value::set(v);
+		Ok(())
+	}
+
 	#[transactional]
 	fn value_commits(v: u32) -> result::Result<u32, &'static str> {
-		Value::set(v);
+		set_value(v)?;
 		Ok(v)
 	}
 
 	#[transactional]
 	fn value_rollbacks(v: u32) -> result::Result<u32, &'static str> {
-		Value::set(v);
+		set_value(v)?;
 		Err("nah")
 	}