From d6c7b2b1ac3a5dc4cc3c15f90e240f3bf3a5c6ea Mon Sep 17 00:00:00 2001
From: Gabriel Ozouf <gabriel.ozouf@numworks.com>
Date: Mon, 31 Aug 2020 11:43:42 +0200
Subject: [PATCH] [poincare/multiplication] Factoring undef power

When factoring 1^inf * 1^-inf with Multiplication::factorizeBase, an
Undef factor would appear an be carried into the reduced multiplication.
We escape early in this situation by returning Undef.

Change-Id: Id826ad3cc131349e5bb460f7a8c82fe606294b97
---
 poincare/src/multiplication.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/poincare/src/multiplication.cpp b/poincare/src/multiplication.cpp
index 3a6f8e9e1..9db2b6c43 100644
--- a/poincare/src/multiplication.cpp
+++ b/poincare/src/multiplication.cpp
@@ -731,6 +731,11 @@ Expression Multiplication::privateShallowReduce(ExpressionNode::ReductionContext
       }
       if (shouldFactorizeBase) {
         factorizeBase(i, i+1, reductionContext);
+        /* An undef term could have appeared when factorizing 1^inf and 1^-inf
+         * for instance. In that case, we escape and return undef. */
+        if (childAtIndex(i).isUndefined()) {
+          return replaceWithUndefinedInPlace();
+        }
         continue;
       }
     } else if (TermHasNumeralBase(oi) && TermHasNumeralBase(oi1) && TermsHaveIdenticalExponent(oi, oi1)) {