Update previous epoch function

2019-02-16 15:09:43 +11:00 · 2019-02-16 15:09:43 +11:00 · f83d02b394
commit f83d02b394
parent b79f0cdf68
1 changed files with 6 additions and 1 deletions
--- a/eth2/types/src/beacon_state.rs
+++ b/eth2/types/src/beacon_state.rs
@ -203,7 +203,12 @@ impl BeaconState {
    ///
    /// Spec v0.2.0
    pub fn previous_epoch(&self, spec: &ChainSpec) -> Epoch {
-        self.current_epoch(spec).saturating_sub(1_u64)
+        let current_epoch = self.current_epoch(&spec);
+        if current_epoch == spec.genesis_epoch {
+            current_epoch
+        } else {
+            current_epoch - 1
+        }
    }

    /// The epoch following `self.current_epoch()`.