From e6d9d245cc325f92f047da9015b073fab46ce37d Mon Sep 17 00:00:00 2001
From: Yuanchao Sun <yuanchao.sun@gmail.com>
Date: Thu, 1 Apr 2021 00:20:49 +0800
Subject: [PATCH] Expose key_owner(), so other pallets can look up validator ID
 by the session key.

---
 frame/session/src/lib.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/frame/session/src/lib.rs b/frame/session/src/lib.rs
index e7b16808f7239..3255bc20af4c6 100644
--- a/frame/session/src/lib.rs
+++ b/frame/session/src/lib.rs
@@ -819,7 +819,8 @@ impl<T: Config> Module<T> {
 		<NextKeys<T>>::insert(v, keys);
 	}
 
-	fn key_owner(id: KeyTypeId, key_data: &[u8]) -> Option<T::ValidatorId> {
+	/// Query the owner of a session key by returning the owner's validator ID.
+	pub fn key_owner(id: KeyTypeId, key_data: &[u8]) -> Option<T::ValidatorId> {
 		<KeyOwner<T>>::get((id, key_data))
 	}