[apps/calculation] Invalid calculation height memoization when leaving

the app.

Fix wrong memoization: in calculation app input '[[1+i, 2][3,4]]', change
the complex format to Polar, go back to the calculation app --> the
calculation height was no recomputed despite the fact that the approximation
output changed.

apps/calculation/calculation.cpp

@@ -33,6 +33,13 @@ Calculation * Calculation::next() const {
   return reinterpret_cast<Calculation *>(const_cast<char *>(result));
 }
 
+void Calculation::tidy() {
+  /* Reset height memoization (the complex format could have changed when
+   * re-entering Calculation app which would impact the heights). */
+  m_height = -1;
+  m_expandedHeight = -1;
+}
+
 const char * Calculation::approximateOutputText() const {
   const char * exactOutput = exactOutputText();
   return exactOutput + strlen(exactOutput) + 1;

apps/calculation/calculation.h

@@ -50,6 +50,8 @@ public:
   bool operator==(const Calculation& c);
   Calculation * next() const;
 
+  void tidy();
+
   // Texts
   const char * inputText() const { return m_inputText; }
   const char * exactOutputText() const { return m_inputText + strlen(m_inputText) + 1; }

apps/calculation/calculation_store.cpp

@@ -141,6 +141,13 @@ void CalculationStore::deleteAll() {
   resetMemoizedModelsAfterCalculationIndex(-1);
 }
 
+void CalculationStore::tidy() {
+  resetMemoizedModelsAfterCalculationIndex(-1);
+  for (Calculation * c : *this) {
+    c->tidy();
+  }
+}
+
 Expression CalculationStore::ansExpression(Context * context) {
   if (numberOfCalculations() == 0) {
     return Rational::Builder(0);

apps/calculation/calculation_store.h

@@ -32,7 +32,7 @@ public:
   void deleteAll();
   int numberOfCalculations() const { return m_numberOfCalculations; }
   Poincare::Expression ansExpression(Poincare::Context * context);
-  void tidy() { resetMemoizedModelsAfterCalculationIndex(-1); }
+  void tidy();
 private:
   static constexpr int k_bufferSize = 10 * 3 * Constant::MaxSerializedExpressionSize;