From 2f7875dec03201de8121dd93c225078f282015ab Mon Sep 17 00:00:00 2001
From: Ethan Frey <ethanfrey@users.noreply.github.com>
Date: Tue, 31 Jan 2017 12:24:49 +0100
Subject: [PATCH] Fixed Coins IsValid, issue #8

---
 types/coin.go      |  2 ++
 types/coin_test.go | 13 +++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/types/coin.go b/types/coin.go
index 94e38b7011..23dc8f0868 100644
--- a/types/coin.go
+++ b/types/coin.go
@@ -35,6 +35,8 @@ func (coins Coins) IsValid() bool {
 			if coin.Amount == 0 {
 				return false
 			}
+			// we compare each coin against the last denom
+			lowDenom = coin.Denom
 		}
 		return true
 	}
diff --git a/types/coin_test.go b/types/coin_test.go
index 00a07a6f36..158f159c50 100644
--- a/types/coin_test.go
+++ b/types/coin_test.go
@@ -42,6 +42,19 @@ func TestCoinsBadSort(t *testing.T) {
 	}
 }
 
+func TestCoinsBadSort2(t *testing.T) {
+	// both are after the first one, but the second and third are in the wrong order
+	coins := Coins{
+		Coin{"GAS", 1},
+		Coin{"TREE", 1},
+		Coin{"MINERAL", 1},
+	}
+
+	if coins.IsValid() {
+		t.Fatal("Coins are not sorted")
+	}
+}
+
 func TestCoinsBadAmount(t *testing.T) {
 	coins := Coins{
 		Coin{"GAS", 1},