From b05abf17cc32ed5232666ef9a47fc348bfd70030 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Wed, 30 May 2018 18:02:11 +0200
Subject: [PATCH] [poincare] Fix getPolynomialCoefficients to avoid overflowing
 the coefficients table

---
 poincare/src/addition.cpp       | 4 ++--
 poincare/src/multiplication.cpp | 6 +++---
 poincare/src/power.cpp          | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/poincare/src/addition.cpp b/poincare/src/addition.cpp
index c51060e2b..b00b56680 100644
--- a/poincare/src/addition.cpp
+++ b/poincare/src/addition.cpp
@@ -37,7 +37,7 @@ int Addition::polynomialDegree(char symbolName) const {
 
 int Addition::getPolynomialCoefficients(char symbolName, Expression * coefficients[]) const {
   int deg = polynomialDegree(symbolName);
-  if (deg < 0 || deg > k_maxNumberOfPolynomialCoefficients-1) {
+  if (deg < 0 || deg > k_maxPolynomialDegree) {
     return -1;
   }
   for (int k = 0; k < deg+1; k++) {
@@ -46,7 +46,7 @@ int Addition::getPolynomialCoefficients(char symbolName, Expression * coefficien
   Expression * intermediateCoefficients[k_maxNumberOfPolynomialCoefficients];
   for (int i = 0; i < numberOfOperands(); i++) {
     int d = operand(i)->getPolynomialCoefficients(symbolName, intermediateCoefficients);
-    assert(d < k_maxNumberOfPolynomialCoefficients-1);
+    assert(d < k_maxNumberOfPolynomialCoefficients);
     for (int j = 0; j < d+1; j++) {
       static_cast<Addition *>(coefficients[j])->addOperand(intermediateCoefficients[j]);
     }
diff --git a/poincare/src/multiplication.cpp b/poincare/src/multiplication.cpp
index f03e06fb0..a4cb4d0c0 100644
--- a/poincare/src/multiplication.cpp
+++ b/poincare/src/multiplication.cpp
@@ -45,15 +45,15 @@ int Multiplication::polynomialDegree(char symbolName) const {
 
 int Multiplication::getPolynomialCoefficients(char symbolName, Expression * coefficients[]) const {
   int deg = polynomialDegree(symbolName);
-  if (deg < 0 || deg + 1 > k_maxNumberOfPolynomialCoefficients) {
+  if (deg < 0 || deg > k_maxPolynomialDegree) {
     return -1;
   }
   int degA = operand(0)->getPolynomialCoefficients(symbolName, coefficients);
-  assert(degA + 1 <= k_maxNumberOfPolynomialCoefficients);
+  assert(degA <= k_maxPolynomialDegree);
   Expression * intermediateCoefficients[k_maxNumberOfPolynomialCoefficients];
   for (int i = 1; i < numberOfOperands(); i++) {
     int degB = operand(i)->getPolynomialCoefficients(symbolName, intermediateCoefficients);
-    assert(degB + 1 <= k_maxNumberOfPolynomialCoefficients);
+    assert(degB <= k_maxPolynomialDegree);
     for (int j = deg; j > 0; j--) {
       Addition * a = new Addition();
       for (int l = 0; l <= j; l++) {
diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index 26d7f32fb..5cc1dc7a3 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -95,7 +95,7 @@ int Power::getPolynomialCoefficients(char symbolName, Expression * coefficients[
       return -1;
     }
     int n = r->numerator().extractedInt();
-    if (n < k_maxNumberOfPolynomialCoefficients) {
+    if (n <= k_maxPolynomialDegree) {
       for (int i = 0; i < n; i++) {
         coefficients[i] = new Rational(0);
       }