eval_error.c: use checking functions

* eval_error.c (error_print): use checking functions instead of
  catching exceptions.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41206 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,7 @@
-Mon Jun 10 15:35:34 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Mon Jun 10 15:36:00 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* eval_error.c (error_print): use checking functions instead of
+	  catching exceptions.
 
 	* eval_error.c (error_print): restore errinfo for the case new
 	  excecption raised while printing the message.  [ruby-core:55365]

eval_error.c

@@ -127,9 +127,9 @@ error_print(void)
     }
 
     eclass = CLASS_OF(errinfo);
-    if (eclass != Qundef) {
+    if (eclass != Qundef &&
-	e = rb_funcall(errinfo, rb_intern("message"), 0, 0);
+	(e = rb_check_funcall(errinfo, rb_intern("message"), 0, 0)) != Qundef &&
-	StringValue(e);
+	(RB_TYPE_P(e, T_STRING) || !NIL_P(e = rb_check_string_type(e)))) {
 	einfo = RSTRING_PTR(e);
 	elen = RSTRING_LEN(e);
     }