From 2e769d81cf90ce648521146f69bb7fd2c77b3c0d Mon Sep 17 00:00:00 2001
From: Jason Turner <jason@emptycrate.com>
Date: Fri, 10 Apr 2015 09:32:01 -0600
Subject: [PATCH] Get return_value_handling fully working

---
 include/chaiscript/dispatchkit/boxed_number.hpp | 6 +++---
 include/chaiscript/dispatchkit/dispatchkit.hpp  | 7 ++++++-
 include/chaiscript/language/chaiscript_eval.hpp | 8 ++++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/include/chaiscript/dispatchkit/boxed_number.hpp b/include/chaiscript/dispatchkit/boxed_number.hpp
index 0042751..1d164e3 100644
--- a/include/chaiscript/dispatchkit/boxed_number.hpp
+++ b/include/chaiscript/dispatchkit/boxed_number.hpp
@@ -232,9 +232,9 @@ namespace chaiscript
           if (t_oper > Operators::boolean_flag && t_oper < Operators::non_const_flag)
           {
             return boolean::go<LHS, RHS>(t_oper, *static_cast<const LHS *>(t_lhs.get_const_ptr()), *static_cast<const RHS *>(t_rhs.get_const_ptr()), t_lhs);
-          } else if (t_oper > Operators::non_const_flag && t_oper < Operators::non_const_int_flag && !t_lhs.is_const()) {
+          } else if (t_oper > Operators::non_const_flag && t_oper < Operators::non_const_int_flag && !t_lhs.is_const() && !t_lhs.is_return_value()) {
             return binary::go<LHS, RHS>(t_oper, *static_cast<LHS *>(t_lhs.get_ptr()), *static_cast<const RHS *>(t_rhs.get_const_ptr()), t_lhs);
-          } else if (t_oper > Operators::non_const_int_flag && t_oper < Operators::const_int_flag && !t_lhs.is_const()) {
+          } else if (t_oper > Operators::non_const_int_flag && t_oper < Operators::const_int_flag && !t_lhs.is_const() && !t_lhs.is_return_value()) {
             return binary_int::go<LHS, RHS>(t_oper, *static_cast<LHS *>(t_lhs.get_ptr()), *static_cast<const RHS *>(t_rhs.get_const_ptr()), t_lhs);
           } else if (t_oper > Operators::const_int_flag && t_oper < Operators::const_flag) {
             return const_binary_int::go<LHS, RHS>(t_oper, *static_cast<const LHS *>(t_lhs.get_const_ptr()), *static_cast<const RHS *>(t_rhs.get_const_ptr()), t_lhs);
@@ -254,7 +254,7 @@ namespace chaiscript
           if (t_oper > Operators::boolean_flag && t_oper < Operators::non_const_flag)
           {
             return boolean::go<LHS, RHS>(t_oper, *static_cast<const LHS *>(t_lhs.get_const_ptr()), *static_cast<const RHS *>(t_rhs.get_const_ptr()), t_lhs);
-          } else if (t_oper > Operators::non_const_flag && t_oper < Operators::non_const_int_flag && !t_lhs.is_const()) {
+          } else if (t_oper > Operators::non_const_flag && t_oper < Operators::non_const_int_flag && !t_lhs.is_const() && !t_lhs.is_return_value()) {
             return binary::go<LHS, RHS>(t_oper, *static_cast<LHS *>(t_lhs.get_ptr()), *static_cast<const RHS *>(t_rhs.get_const_ptr()), t_lhs);
           } else if (t_oper > Operators::non_const_int_flag && t_oper < Operators::const_int_flag) {
             throw chaiscript::detail::exception::bad_any_cast();
diff --git a/include/chaiscript/dispatchkit/dispatchkit.hpp b/include/chaiscript/dispatchkit/dispatchkit.hpp
index 46155ca..cb80acf 100644
--- a/include/chaiscript/dispatchkit/dispatchkit.hpp
+++ b/include/chaiscript/dispatchkit/dispatchkit.hpp
@@ -795,7 +795,12 @@ namespace chaiscript
 
         Boxed_Value call_function(const std::string &t_name, const std::vector<Boxed_Value> &params) const
         {
-          return dispatch::dispatch(get_function(t_name), params, m_conversions);
+          Boxed_Value bv = dispatch::dispatch(get_function(t_name), params, m_conversions);
+          // the result of a clone is never to be marked as a return_value
+          if (t_name == "clone") {
+            bv.reset_return_value();
+          }
+          return bv;
         }
 
         Boxed_Value call_function(const std::string &t_name) const
diff --git a/include/chaiscript/language/chaiscript_eval.hpp b/include/chaiscript/language/chaiscript_eval.hpp
index b7eb0a6..59e09ba 100644
--- a/include/chaiscript/language/chaiscript_eval.hpp
+++ b/include/chaiscript/language/chaiscript_eval.hpp
@@ -558,6 +558,10 @@ namespace chaiscript
               throw exception::eval_error("Error with unsupported arithmetic assignment operation");
             }
           } else if (m_oper == Operators::assign) {
+            if (lhs.is_return_value()) {
+              throw exception::eval_error("Error, cannot assign to temporary value.");
+            }
+
             try {
               if (lhs.is_undef()) {
                 if (!this->children.empty() && 
@@ -567,14 +571,14 @@ namespace chaiscript
                   /// \todo This does not handle the case of an unassigned reference variable
                   ///       being assigned outside of its declaration
                   lhs.assign(rhs);
+                  lhs.reset_return_value();
                   return rhs;
                 } else {
                   if (!rhs.is_return_value())
                   {
                     rhs = t_ss.call_function("clone", rhs);
-                  } else {
-                    rhs.reset_return_value();
                   }
+                  rhs.reset_return_value();
                 }
               }