[poincare] Move Power vs Unit checks to Power::shallowReduce

poincare/src/power.cpp

@@ -387,9 +387,18 @@ Expression Power::shallowReduce(ExpressionNode::ReductionContext reductionContex
   Expression base = childAtIndex(0);
   Expression index = childAtIndex(1);
 
-  // Step 1: There should be no unit in the index!
-  if (index.hasUnit()) {
-    return replaceWithUndefinedInPlace();
+  // Step 1: Handle the units
+  {
+    if (index.hasUnit()) {
+      // There must be no unit in the exponent
+      return replaceWithUndefinedInPlace();
+    }
+    if (base.hasUnit()) {
+      if (index.type() != ExpressionNode::Type::Rational || !static_cast<Rational &>(index).isInteger()) {
+        // The exponent must be an Integer
+        return replaceWithUndefinedInPlace();
+      }
+    }
   }
 
   // Step 2: Handle matrices

poincare/src/unit.cpp

@@ -323,12 +323,7 @@ Expression Unit::shallowBeautify(ExpressionNode::ReductionContext reductionConte
     m.addChildAtIndexInPlace(*this, 1, 1);
     return std::move(m);
   }
-  // Check that the exponent, if any, of a Unit is an integer
   if (!ancestor.isUninitialized() && ancestor.type() == ExpressionNode::Type::Power) {
-    Expression exponent = ancestor.childAtIndex(1);
-    if (!(exponent.type() == ExpressionNode::Type::Rational && static_cast<Rational &>(exponent).isInteger())) {
-      goto UnitCheckUnsuccessful;
-    }
     ancestor = ancestor.parent();
   }
   /* Check homogeneity: at this point, ancestor must be
@@ -344,7 +339,6 @@ Expression Unit::shallowBeautify(ExpressionNode::ReductionContext reductionConte
   if (ancestor.isUninitialized()) {
     return *this;
   }
-  UnitCheckUnsuccessful:
   /* If the latter checks are not successfully passed, then the function
    * returns replaceWithUndefinedInPlace.
    * TODO Something else should be returned in order to report a more