From 830362416d7edf157086c8af9aa5232f51251be9 Mon Sep 17 00:00:00 2001
From: RunasSudo <runassudo@yingtongli.me>
Date: Fri, 4 Jun 2021 22:54:26 +1000
Subject: [PATCH] Fix logic error where loss by fraction not updated in
 multi-stage exclusions

---
 src/stv/mod.rs     |  8 +++-----
 tests/utils/mod.rs | 11 +++++++++--
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/stv/mod.rs b/src/stv/mod.rs
index c41ba46..91f4da0 100644
--- a/src/stv/mod.rs
+++ b/src/stv/mod.rs
@@ -825,8 +825,6 @@ where
 			let count_card = state.candidates.get_mut(excluded_candidate).unwrap();
 			checksum -= &result.total_votes;
 			count_card.transfer(&-result.total_votes);
-			
-			// By definition, there is no loss by fraction
 		}
 	}
 	
@@ -837,14 +835,14 @@ where
 		count_card.transfers = -count_card.votes.clone();
 		count_card.votes = N::new();
 		
-		// Update loss by fraction
-		state.loss_fraction.transfer(&-checksum);
-		
 		if let ExclusionMethod::SingleStage = opts.exclusion {
 		} else {
 			state.logger.log_literal("Exclusion complete.".to_string());
 		}
 	}
+	
+	// Update loss by fraction
+	state.loss_fraction.transfer(&-checksum);
 }
 
 fn finished_before_stage<N: Number>(state: &CountState<N>) -> bool {
diff --git a/tests/utils/mod.rs b/tests/utils/mod.rs
index bd0325b..9953ba2 100644
--- a/tests/utils/mod.rs
+++ b/tests/utils/mod.rs
@@ -80,12 +80,19 @@ where
 fn validate_stage<N: Number>(idx: usize, state: &CountState<N>, records: &Vec<StringRecord>) {
 	println!("Col at idx {}", idx);
 	
-	// Validate candidate votes
-	//let mut candidate_votes: Vec<N> = records.iter().skip(2).map(|r| N::parse(&r[idx*2 + 1])).collect();
 	let mut candidate_votes: Vec<N> = records.iter().skip(2).map(|r| N::from(r[idx*2 + 1].parse::<f64>().expect("Syntax Error"))).collect();
+	
+	// Validate exhausted/LBF
+	let lbf_votes = candidate_votes.pop().unwrap();
+	let exhausted_votes = candidate_votes.pop().unwrap();
+	
+	assert!(state.exhausted.votes == exhausted_votes);
+	assert!(state.loss_fraction.votes == lbf_votes);
+	
 	// Remove exhausted/LBF rows
 	candidate_votes.truncate(candidate_votes.len() - 2);
 	
+	// Validate candidate votes
 	for (candidate, votes) in state.election.candidates.iter().zip(candidate_votes) {
 		let count_card = state.candidates.get(candidate).unwrap();
 		assert!(count_card.votes == votes, "Failed to validate votes for candidate {}. Expected {:}, got {:}", candidate.name, votes, count_card.votes);