From b311e966032b95a9448a58d9c5f4a0a29ce38694 Mon Sep 17 00:00:00 2001
From: yancy <yancy@yancy.lol>
Date: Wed, 8 Mar 2023 12:07:18 +0100
Subject: [PATCH] Fix weight subtract bug

---
 bitcoin/src/blockdata/weight.rs | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/bitcoin/src/blockdata/weight.rs b/bitcoin/src/blockdata/weight.rs
index 7bccaf2c..af45e657 100644
--- a/bitcoin/src/blockdata/weight.rs
+++ b/bitcoin/src/blockdata/weight.rs
@@ -86,7 +86,7 @@ impl Weight {
     ///
     /// Computes `self - rhs` returning `None` if overflow occurred.
     pub fn checked_sub(self, rhs: Self) -> Option<Self> {
-        self.0.checked_add(rhs.0).map(Self)
+        self.0.checked_sub(rhs.0).map(Self)
     }
 
     /// Checked multiplication.
@@ -115,6 +115,20 @@ impl fmt::Display for Weight {
     }
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn checked_sub_test(){
+        let result = Weight(1).checked_sub(Weight(1)).expect("expected weight unit");
+        assert_eq!(Weight::ZERO, result);
+
+        let result = Weight::MIN.checked_sub(Weight(1));
+        assert_eq!(None, result);
+    }
+}
+
 impl From<Weight> for u64 {
     fn from(value: Weight) -> Self {
         value.to_wu()