From 54ed32ed42c2abb00545214a5c69626a0d13cc9d Mon Sep 17 00:00:00 2001
From: thiolliere <gui.thiolliere@gmail.com>
Date: Fri, 19 Jun 2020 13:41:23 +0200
Subject: [PATCH] llow decl-module to have a where clause with trailing comma

---
 frame/support/src/dispatch.rs      | 3 ++-
 frame/support/test/tests/system.rs | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/frame/support/src/dispatch.rs b/frame/support/src/dispatch.rs
index edb6e62639642..d9a3561802c8f 100644
--- a/frame/support/src/dispatch.rs
+++ b/frame/support/src/dispatch.rs
@@ -283,7 +283,7 @@ macro_rules! decl_module {
 			$trait_instance:ident: $trait_name:ident
 			$( <I>, I: $instantiable:path $( = $module_default_instance:path )? )?
 		>
-		for enum $call_type:ident where origin: $origin_type:ty $(, $where_ty:ty: $where_bound:path )* {
+		for enum $call_type:ident where origin: $origin_type:ty $(, $where_ty:ty: $where_bound:path )* $(,)? {
 			$( $t:tt )*
 		}
 	) => {
@@ -317,6 +317,7 @@ macro_rules! decl_module {
 			origin: $origin_type:ty,
 			system = $system:ident
 			$(, $where_ty:ty: $where_bound:path )*
+			$(,)?
 		{
 			$($t:tt)*
 		}
diff --git a/frame/support/test/tests/system.rs b/frame/support/test/tests/system.rs
index c3c47d2065130..0d6a22fd1a3e1 100644
--- a/frame/support/test/tests/system.rs
+++ b/frame/support/test/tests/system.rs
@@ -31,7 +31,7 @@ pub trait Trait: 'static + Eq + Clone {
 }
 
 frame_support::decl_module! {
-	pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
+	pub struct Module<T: Trait> for enum Call where origin: T::Origin, {}
 }
 
 impl<T: Trait> Module<T> {