Fail fast if sympify fails

Author: isuruf

ext/symengine/symengine.h

@@ -1,7 +1,8 @@
 #ifndef SYMENGINE_H_
 #define SYMENGINE_H_
 
-#include "ruby.h"
+#include <ruby/ruby.h>
+#include <ruby/intern.h>
 
 //variable name for a module starts with m
 VALUE m_symengine;

ext/symengine/symengine_utils.c

@@ -60,17 +60,20 @@ void sympify(VALUE operand2, basic_struct *cbasic_operand2) {
             break;
 
         case T_DATA:
+            if (rb_obj_is_kind_of(operand2, c_basic)) {
+                Data_Get_Struct(operand2, basic_struct, temp);
+                basic_assign(cbasic_operand2, temp);
+                break;
+            }
             #ifdef HAVE_SYMENGINE_MPFR
             if (strcmp(rb_obj_classname(operand2), "BigDecimal") == 0) {
                 c = RSTRING_PTR( rb_funcall(operand2, rb_intern("to_s"), 1, rb_str_new2("F")) );
                 real_mpfr_set_str(cbasic_operand2, c, 200);
                 break;
             }
             #endif //HAVE_SYMENGINE_MPFR
-
-            Data_Get_Struct(operand2, basic_struct, temp);
-            basic_assign(cbasic_operand2, temp);
-            break;
+        default:
+            rb_raise(rb_eTypeError, "%s can't be coerced into SymEngine::Basic", rb_obj_classname(operand2));
     }
 }