add failing test for itamar

frame/staking/src/tests.rs

@@ -5102,6 +5102,21 @@ fn proportional_ledger_slash_works() {
 	assert_eq!(LedgerSlashPerEra::get().0, 0);
 	assert_eq!(LedgerSlashPerEra::get().1, BTreeMap::from([(6, 30), (7, 30)]));
 
+	// Given
+	ledger.unlocking = bounded_vec![c(4, 100), c(5, 100), c(6, 100), c(7, 100)];
+	ledger.total = 4 * 100;
+	ledger.active = 0;
+	// When the first 2 chunks don't overlap with the affected range of unlock eras.
+	assert_eq!(ledger.slash(15, 0, 3), 15);
+	// Then
+	assert_eq!(ledger.unlocking, vec![c(4, 100), c(5, 99), c(6, 100 - 7), c(7, 100 - 7)]);
+	// ISSUE: The sum of everything we round down is affecting chunk 5, which should have ideally
+	// remained unchanged.
+	assert_eq!(ledger.total, 4 * 100 - 15);
+	assert_eq!(LedgerSlashPerEra::get().0, 0);
+	assert_eq!(LedgerSlashPerEra::get().1, BTreeMap::from([(5, 99), (6, 93), (7, 93)]));
+	panic!();
+
 	// Given
 	ledger.unlocking = bounded_vec![c(4, 40), c(5, 100), c(6, 10), c(7, 250)];
 	ledger.active = 500;