From 8f2a6c3122fc82be89d96aa802e7e8dd4ebf286a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Mon, 17 Apr 2017 14:17:45 +0200
Subject: [PATCH] [apps/sequence] Cap the sum of terms to a maximum number of
 terms

Change-Id: Ib9abcdc92cef5e4e188a81c319b20be2c8b7ab72
---
 apps/sequence/sequence.cpp | 3 +++
 apps/sequence/sequence.h   | 1 +
 2 files changed, 4 insertions(+)

diff --git a/apps/sequence/sequence.cpp b/apps/sequence/sequence.cpp
index de99deda6..7bf5144f0 100644
--- a/apps/sequence/sequence.cpp
+++ b/apps/sequence/sequence.cpp
@@ -274,6 +274,9 @@ float Sequence::evaluateAtAbscissa(float x, Poincare::Context * context) const {
 
 float Sequence::sumOfTermsBetweenAbscissa(float start, float end, Context * context) {
   float result = 0.0f;
+  if (end-start > k_maxNumberOfTermsInSum) {
+    return NAN;
+  }
   for (float i = roundf(start); i <= roundf(end); i = i + 1.0f) {
     result += evaluateAtAbscissa(i, context);
   }
diff --git a/apps/sequence/sequence.h b/apps/sequence/sequence.h
index b8811487e..23547f431 100644
--- a/apps/sequence/sequence.h
+++ b/apps/sequence/sequence.h
@@ -35,6 +35,7 @@ public:
   float sumOfTermsBetweenAbscissa(float start, float end, Poincare::Context * context);
 private:
   constexpr static int k_maxRecurrentRank = 10000;
+  constexpr static float k_maxNumberOfTermsInSum = 100000.0f;
   char symbol() const override;
   Type m_type;
   char m_firstInitialConditionText[TextField::maxBufferSize()];