From e116a82bc8a4978163249fe07a706a07cc3dac88 Mon Sep 17 00:00:00 2001
From: Gautam Botrel <gautam.botrel@gmail.com>
Date: Fri, 12 Nov 2021 17:49:47 -0600
Subject: [PATCH] fix: incorrect handling of hints in r1cs solver

---
 internal/backend/bls12-377/cs/r1cs.go                      | 7 ++++++-
 internal/backend/bls12-381/cs/r1cs.go                      | 7 ++++++-
 internal/backend/bls24-315/cs/r1cs.go                      | 7 ++++++-
 internal/backend/bn254/cs/r1cs.go                          | 7 ++++++-
 internal/backend/bw6-761/cs/r1cs.go                        | 7 ++++++-
 .../backend/template/representations/r1cs.go.tmpl          | 7 ++++++-
 6 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/internal/backend/bls12-377/cs/r1cs.go b/internal/backend/bls12-377/cs/r1cs.go
index c0c39f92ac..e21c870eae 100644
--- a/internal/backend/bls12-377/cs/r1cs.go
+++ b/internal/backend/bls12-377/cs/r1cs.go
@@ -208,7 +208,12 @@ func (cs *R1CS) solveConstraint(r compiled.R1C, solution *solution) error {
 
 		// first we check if this is a hint wire
 		if hint, ok := cs.MHints[vID]; ok {
-			return solution.solveWithHint(vID, hint)
+			if err := solution.solveWithHint(vID, hint); err != nil {
+				return err
+			}
+			v := solution.computeTerm(t)
+			val.Add(val, &v)
+			return nil
 		}
 
 		if loc != 0 {
diff --git a/internal/backend/bls12-381/cs/r1cs.go b/internal/backend/bls12-381/cs/r1cs.go
index fd5065ce66..ba9333b1e4 100644
--- a/internal/backend/bls12-381/cs/r1cs.go
+++ b/internal/backend/bls12-381/cs/r1cs.go
@@ -208,7 +208,12 @@ func (cs *R1CS) solveConstraint(r compiled.R1C, solution *solution) error {
 
 		// first we check if this is a hint wire
 		if hint, ok := cs.MHints[vID]; ok {
-			return solution.solveWithHint(vID, hint)
+			if err := solution.solveWithHint(vID, hint); err != nil {
+				return err
+			}
+			v := solution.computeTerm(t)
+			val.Add(val, &v)
+			return nil
 		}
 
 		if loc != 0 {
diff --git a/internal/backend/bls24-315/cs/r1cs.go b/internal/backend/bls24-315/cs/r1cs.go
index ddbab50d06..bd726a6152 100644
--- a/internal/backend/bls24-315/cs/r1cs.go
+++ b/internal/backend/bls24-315/cs/r1cs.go
@@ -208,7 +208,12 @@ func (cs *R1CS) solveConstraint(r compiled.R1C, solution *solution) error {
 
 		// first we check if this is a hint wire
 		if hint, ok := cs.MHints[vID]; ok {
-			return solution.solveWithHint(vID, hint)
+			if err := solution.solveWithHint(vID, hint); err != nil {
+				return err
+			}
+			v := solution.computeTerm(t)
+			val.Add(val, &v)
+			return nil
 		}
 
 		if loc != 0 {
diff --git a/internal/backend/bn254/cs/r1cs.go b/internal/backend/bn254/cs/r1cs.go
index 8314157dee..50823245b8 100644
--- a/internal/backend/bn254/cs/r1cs.go
+++ b/internal/backend/bn254/cs/r1cs.go
@@ -208,7 +208,12 @@ func (cs *R1CS) solveConstraint(r compiled.R1C, solution *solution) error {
 
 		// first we check if this is a hint wire
 		if hint, ok := cs.MHints[vID]; ok {
-			return solution.solveWithHint(vID, hint)
+			if err := solution.solveWithHint(vID, hint); err != nil {
+				return err
+			}
+			v := solution.computeTerm(t)
+			val.Add(val, &v)
+			return nil
 		}
 
 		if loc != 0 {
diff --git a/internal/backend/bw6-761/cs/r1cs.go b/internal/backend/bw6-761/cs/r1cs.go
index d672fcbd03..37b383b43c 100644
--- a/internal/backend/bw6-761/cs/r1cs.go
+++ b/internal/backend/bw6-761/cs/r1cs.go
@@ -208,7 +208,12 @@ func (cs *R1CS) solveConstraint(r compiled.R1C, solution *solution) error {
 
 		// first we check if this is a hint wire
 		if hint, ok := cs.MHints[vID]; ok {
-			return solution.solveWithHint(vID, hint)
+			if err := solution.solveWithHint(vID, hint); err != nil {
+				return err
+			}
+			v := solution.computeTerm(t)
+			val.Add(val, &v)
+			return nil
 		}
 
 		if loc != 0 {
diff --git a/internal/generator/backend/template/representations/r1cs.go.tmpl b/internal/generator/backend/template/representations/r1cs.go.tmpl
index 5e0574a76b..a584b052d9 100644
--- a/internal/generator/backend/template/representations/r1cs.go.tmpl
+++ b/internal/generator/backend/template/representations/r1cs.go.tmpl
@@ -202,7 +202,12 @@ func (cs *R1CS) solveConstraint(r compiled.R1C, solution *solution) error {
 
 		// first we check if this is a hint wire
 		if hint, ok := cs.MHints[vID]; ok {
-			return solution.solveWithHint(vID, hint)
+			if err := solution.solveWithHint(vID, hint); err != nil {
+				return err
+			}
+			v := solution.computeTerm(t)
+			val.Add(val, &v)
+			return nil
 		}
 
 		if loc != 0 {