From d6b577b7dcd23a568fcc7cc78014d27a099fb33f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Mon, 18 Dec 2017 10:42:16 +0100
Subject: [PATCH] [poincare] Do not apply a^(b+c)->a^b*a^c when a is null
 (0^(5-2) != 0^5*0^(-2))

---
 poincare/src/power.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index 36c251107..64b029aec 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -338,8 +338,8 @@ Expression * Power::shallowReduce(Context& context, AngleUnit angleUnit) {
       }
     }
   }
-  // a^(b+c) -> Rational(a^b)*a^c with a and b rational
-  if (!letPowerAtRoot && operand(0)->type() == Type::Rational && operand(1)->type() == Type::Addition) {
+  // a^(b+c) -> Rational(a^b)*a^c with a and b rational and a != 0
+  if (!letPowerAtRoot && operand(0)->type() == Type::Rational && !static_cast<const Rational *>(operand(0))->isZero() && operand(1)->type() == Type::Addition) {
     Addition * a = static_cast<Addition *>(editableOperand(1));
     // Check is b is rational
     if (a->operand(0)->type() == Type::Rational) {