From 66d026bcda634f7d81892670531e6d1d5047eb73 Mon Sep 17 00:00:00 2001
From: Christoph Otter <chris@confio.gmbh>
Date: Mon, 15 May 2023 13:04:01 +0200
Subject: [PATCH] Check for missing amount when parsing Coin

---
 packages/std/src/coin.rs             | 24 ++++++++++++++++++++----
 packages/std/src/errors/std_error.rs |  2 ++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/packages/std/src/coin.rs b/packages/std/src/coin.rs
index 9c8798a005..b88a6da3ee 100644
--- a/packages/std/src/coin.rs
+++ b/packages/std/src/coin.rs
@@ -28,6 +28,10 @@ impl FromStr for Coin {
             .ok_or(CoinFromStrError::MissingDenom)?;
         let (amount, denom) = s.split_at(pos);
 
+        if amount.is_empty() {
+            return Err(CoinFromStrError::MissingAmount);
+        }
+
         Ok(Coin {
             amount: amount.parse::<u128>()?.into(),
             denom: denom.to_string(),
@@ -205,12 +209,24 @@ mod tests {
             CoinFromStrError::MissingDenom
         );
         assert_eq!(
-            Coin::from_str("ucosm").unwrap_err().to_string(),
-            "Invalid amount: cannot parse integer from empty string"
+            Coin::from_str("ucosm").unwrap_err(), // no amount
+            CoinFromStrError::MissingAmount
+        );
+        assert_eq!(
+            Coin::from_str("-123ucosm").unwrap_err(), // negative amount
+            CoinFromStrError::MissingAmount
+        );
+        assert_eq!(
+            Coin::from_str("").unwrap_err(), // empty input
+            CoinFromStrError::MissingDenom
+        );
+        assert_eq!(
+            Coin::from_str(" 1ucosm").unwrap_err(), // unsupported whitespace
+            CoinFromStrError::MissingAmount
         );
         assert_eq!(
-            Coin::from_str("-123ucosm").unwrap_err().to_string(),
-            "Invalid amount: cannot parse integer from empty string"
+            Coin::from_str("�1ucosm").unwrap_err(), // other broken data
+            CoinFromStrError::MissingAmount
         );
         assert_eq!(
             Coin::from_str("340282366920938463463374607431768211456ucosm")
diff --git a/packages/std/src/errors/std_error.rs b/packages/std/src/errors/std_error.rs
index 7093167590..d90171c74c 100644
--- a/packages/std/src/errors/std_error.rs
+++ b/packages/std/src/errors/std_error.rs
@@ -594,6 +594,8 @@ pub struct RoundUpOverflowError;
 pub enum CoinFromStrError {
     #[error("Missing denominator")]
     MissingDenom,
+    #[error("Missing amount or non-digit characters in amount")]
+    MissingAmount,
     #[error("Invalid amount: {0}")]
     InvalidAmount(std::num::ParseIntError),
 }