ExpressionParser: Return unique_ptr from copy (#27098)

- We need copy().release() on many of these calls because nodes in the
  tree call 'copy' explicitly. It's not really different to the code
  that's there now, but it's not pretty either. Some of these will go
  away in the upcoming commit

src/App/Expression.cpp

@@ -1025,7 +1025,7 @@ ExpressionPtr Expression::importSubNames(const std::map<std::string,std::string>
     ImportSubNamesExpressionVisitor v(subNameMap);
     auto res = copy();
     res->visit(v);
-    return ExpressionPtr(res);
+    return res;
 }
 
 class UpdateLabelExpressionVisitor : public ExpressionVisitor {
@@ -1057,7 +1057,7 @@ ExpressionPtr Expression::updateLabelReference(
             UpdateLabelExpressionVisitor v(obj,ref,newLabel);
             auto expr = copy();
             expr->visit(v);
-            return ExpressionPtr(expr);
+            return expr;
         }
     }
     return {};
@@ -1102,7 +1102,7 @@ ExpressionPtr Expression::replaceObject(const DocumentObject *parent,
     auto expr = copy();
     v.collect = false;
     expr->visit(v);
-    return ExpressionPtr(expr);
+    return expr;
 }
 
 App::any Expression::getValueAsAny() const {
@@ -1177,8 +1177,9 @@ void Expression::toString(std::ostream &ss, bool persistent, bool checkPriority,
         c->toString(ss,persistent);
 }
 
-Expression* Expression::copy() const {
-    auto expr = _copy();
+ExpressionPtr Expression::copy() const
+{
+    auto expr = std::unique_ptr<Expression>(_copy());
     copy_vector(expr->components,components);
     expr->comment = comment;
     return expr;
@@ -1259,7 +1260,7 @@ NumberExpression::NumberExpression(const DocumentObject *_owner, const Quantity
 
 Expression *NumberExpression::simplify() const
 {
-    return copy();
+    return copy().release();
 }
 
 Expression *NumberExpression::_copy() const
@@ -1556,7 +1557,7 @@ void OperatorExpression::_toString(std::ostream &s, bool persistent,int) const
 
 Expression *OperatorExpression::_copy() const
 {
-    return new OperatorExpression(owner, left->copy(), op, right->copy());
+    return new OperatorExpression(owner, left->copy().release(), op, right->copy().release());
 }
 
 int OperatorExpression::priority() const
@@ -2770,7 +2771,7 @@ Expression *FunctionExpression::_copy() const
     std::vector<Expression*> a;
 
     while (i != args.end()) {
-        a.push_back((*i)->copy());
+        a.push_back((*i)->copy().release());
         ++i;
     }
     return new FunctionExpression(owner, f, std::string(fname), std::move(a));
@@ -2879,7 +2880,7 @@ void VariableExpression::_toString(std::ostream &ss, bool persistent,int) const
 
 Expression *VariableExpression::simplify() const
 {
-    return copy();
+    return copy().release();
 }
 
 Expression *VariableExpression::_copy() const
@@ -3084,7 +3085,7 @@ StringExpression::~StringExpression() {
 
 Expression *StringExpression::simplify() const
 {
-    return copy();
+    return copy().release();
 }
 
 void StringExpression::_toString(std::ostream &ss, bool,int) const
@@ -3168,7 +3169,12 @@ void ConditionalExpression::_toString(std::ostream &ss, bool persistent,int) con
 
 Expression *ConditionalExpression::_copy() const
 {
-    return new ConditionalExpression(owner, condition->copy(), trueExpr->copy(), falseExpr->copy());
+    return new ConditionalExpression(
+        owner,
+        condition->copy().release(),
+        trueExpr->copy().release(),
+        falseExpr->copy().release()
+    );
 }
 
 int ConditionalExpression::priority() const
@@ -3266,7 +3272,7 @@ Expression *RangeExpression::_copy() const
 
 Expression *RangeExpression::simplify() const
 {
-    return copy();
+    return copy().release();
 }
 
 void RangeExpression::_getIdentifiers(std::map<App::ObjectIdentifier,bool> &deps) const

src/App/Expression.h

@@ -366,7 +366,7 @@ public:
     static ExpressionPtr parse(const App::DocumentObject* owner, const std::string& buffer);
 
     /// Copy an expression.
-    Expression * copy() const;
+    ExpressionPtr copy() const;
 
     /**
      * @brief Get the operator priority.

src/App/ExpressionParser.h

@@ -542,7 +542,7 @@ public:
     void setPyValue(PyObject* pyobj, bool owned = false);
     Expression* simplify() const override
     {
-        return copy();
+        return copy().release();
     }
 
 protected:

src/Mod/Spreadsheet/App/PropertySheet.cpp

@@ -2086,10 +2086,10 @@ PropertySheet::BindingType PropertySheet::getBinding(
                     }
                 }
                 if (pStart) {
-                    pStart->reset(expr->getArgs()[1]->copy());
+                    *pStart = expr->getArgs()[1]->copy();
                 }
                 if (pEnd) {
-                    pEnd->reset(expr->getArgs()[2]->copy());
+                    *pEnd = expr->getArgs()[2]->copy();
                 }
                 return href ? BindingHiddenRef : BindingNormal;
             }