From b477880a3b9c097b65b1e006d8116f3998cf013c Mon Sep 17 00:00:00 2001
From: Pascal Berrang <pb.pascal@gmail.com>
Date: Thu, 23 Mar 2023 21:53:45 +0000
Subject: [PATCH] Fix base scalar multiplication (#117)

---
 CHANGELOG.md                               | 1 +
 src/groups/curves/short_weierstrass/mod.rs | 2 +-
 src/groups/mod.rs                          | 2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 396764a..2f7fa41 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # CHANGELOG
 
 ## Pending
+- [\#117](https://github.com/arkworks-rs/r1cs-std/pull/117) Fix result of `precomputed_base_scalar_mul_le` to not discard previous value.
 
 ### Breaking changes
 
diff --git a/src/groups/curves/short_weierstrass/mod.rs b/src/groups/curves/short_weierstrass/mod.rs
index 91eae94..b41d959 100644
--- a/src/groups/curves/short_weierstrass/mod.rs
+++ b/src/groups/curves/short_weierstrass/mod.rs
@@ -559,7 +559,7 @@ where
             .map(|(b, c)| (b.borrow().clone(), *c))
             .unzip();
         let base = bases[0];
-        *self = Self::constant(base).scalar_mul_le(bits.iter())?;
+        *self += Self::constant(base).scalar_mul_le(bits.iter())?;
         Ok(())
     }
 }
diff --git a/src/groups/mod.rs b/src/groups/mod.rs
index a02e303..fb8c746 100644
--- a/src/groups/mod.rs
+++ b/src/groups/mod.rs
@@ -134,7 +134,7 @@ pub trait CurveVar<C: CurveGroup, ConstraintF: Field>:
             // else, set self = self;
             result = bit.borrow().select(&self_plus_base, &result)?;
         }
-        *self = result;
+        *self += result;
         Ok(())
     }