From 8891b70fe284f2d0a294f13d9a5afbca26a20513 Mon Sep 17 00:00:00 2001
From: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Date: Tue, 16 Apr 2024 13:08:26 +0300
Subject: [PATCH] [pallet-broker] Use saturating math in input validation
 (#4151)

Changes:
- Saturate in the input validation of he drop history function or
pallet-broker.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
---
 prdoc/pr_4151.prdoc                              | 11 +++++++++++
 substrate/frame/broker/src/dispatchable_impls.rs |  5 ++++-
 substrate/frame/broker/src/tests.rs              |  1 +
 3 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 prdoc/pr_4151.prdoc

diff --git a/prdoc/pr_4151.prdoc b/prdoc/pr_4151.prdoc
new file mode 100644
index 0000000000..70b9f5e60e
--- /dev/null
+++ b/prdoc/pr_4151.prdoc
@@ -0,0 +1,11 @@
+title: "[pallet-broker] Use saturating math in input validation"
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      Use saturating in the pallet-broker input validation of the `drop_history` extrinsic. This
+      fixes a safeguard that only expired historic instantaneous pool records get dropped.
+
+crates:
+  - name: pallet-broker
+    bump: patch
diff --git a/substrate/frame/broker/src/dispatchable_impls.rs b/substrate/frame/broker/src/dispatchable_impls.rs
index c2e731462c..b43911b6bc 100644
--- a/substrate/frame/broker/src/dispatchable_impls.rs
+++ b/substrate/frame/broker/src/dispatchable_impls.rs
@@ -419,7 +419,10 @@ impl<T: Config> Pallet<T> {
 	pub(crate) fn do_drop_history(when: Timeslice) -> DispatchResult {
 		let config = Configuration::<T>::get().ok_or(Error::<T>::Uninitialized)?;
 		let status = Status::<T>::get().ok_or(Error::<T>::Uninitialized)?;
-		ensure!(status.last_timeslice > when + config.contribution_timeout, Error::<T>::StillValid);
+		ensure!(
+			status.last_timeslice > when.saturating_add(config.contribution_timeout),
+			Error::<T>::StillValid
+		);
 		let record = InstaPoolHistory::<T>::take(when).ok_or(Error::<T>::NoHistory)?;
 		if let Some(payout) = record.maybe_payout {
 			let _ = Self::charge(&Self::account_id(), payout);
diff --git a/substrate/frame/broker/src/tests.rs b/substrate/frame/broker/src/tests.rs
index d738d34450..8ec0c6d158 100644
--- a/substrate/frame/broker/src/tests.rs
+++ b/substrate/frame/broker/src/tests.rs
@@ -146,6 +146,7 @@ fn drop_history_works() {
 			advance_to(16);
 			assert_eq!(InstaPoolHistory::<Test>::iter().count(), 6);
 			advance_to(17);
+			assert_noop!(Broker::do_drop_history(u32::MAX), Error::<Test>::StillValid);
 			assert_noop!(Broker::do_drop_history(region.begin), Error::<Test>::StillValid);
 			advance_to(18);
 			assert_eq!(InstaPoolHistory::<Test>::iter().count(), 6);