1 files changed, 43 insertions, 6 deletions

diff --git a/object.c b/object.c
index 42d9d2509b..cad41e686c 100644
--- a/object.c
+++ b/object.c
@@ -1833,8 +1833,14 @@ rb_mod_const_defined(int argc, VALUE *argv, VALUE mod)
     else {
 	rb_scan_args(argc, argv, "11", &name, &recur);
     }
-    if (!(id = rb_check_id(name)) && rb_is_const_name(name))
-	return Qfalse;
+    if (!(id = rb_check_id(name))) {
+	if (rb_is_const_name(name)) {
+	    return Qfalse;
+	}
+	else {
+	    rb_name_error_str(name, "wrong constant name %s", RSTRING_PTR(name));
+	}
+    }
     if (!rb_is_const_id(id)) {
 	rb_name_error(id, "wrong constant name %s", rb_id2name(id));
     }
@@ -1864,8 +1870,16 @@ rb_mod_const_defined(int argc, VALUE *argv, VALUE mod)
 static VALUE
 rb_obj_ivar_get(VALUE obj, VALUE iv)
 {
-    ID id = rb_to_id(iv);
+    ID id = rb_check_id(iv);
 
+    if (!id) {
+	if (rb_is_instance_name(iv)) {
+	    return Qnil;
+	}
+	else {
+	    rb_name_error_str(iv, "`%s' is not allowed as an instance variable name", RSTRING_PTR(iv));
+	}
+    }
     if (!rb_is_instance_id(id)) {
 	rb_name_error(id, "`%s' is not allowed as an instance variable name", rb_id2name(id));
     }
@@ -1926,7 +1940,14 @@ rb_obj_ivar_defined(VALUE obj, VALUE iv)
 {
     ID id = rb_check_id(iv);
 
-    if (!id && rb_is_instance_name(iv)) return Qfalse;
+    if (!id) {
+	if (rb_is_instance_name(iv)) {
+	    return Qfalse;
+	}
+	else {
+	    rb_name_error_str(iv, "`%s' is not allowed as an instance variable name", RSTRING_PTR(iv));
+	}
+    }
     if (!rb_is_instance_id(id)) {
 	rb_name_error(id, "`%s' is not allowed as an instance variable name", rb_id2name(id));
     }
@@ -1950,8 +1971,17 @@ rb_obj_ivar_defined(VALUE obj, VALUE iv)
 static VALUE
 rb_mod_cvar_get(VALUE obj, VALUE iv)
 {
-    ID id = rb_to_id(iv);
+    ID id = rb_check_id(iv);
 
+    if (!id) {
+	if (rb_is_class_name(iv)) {
+	    rb_name_error_str(iv, "uninitialized class variable %s in %s",
+			      RSTRING_PTR(iv), rb_class2name(obj));
+	}
+	else {
+	    rb_name_error_str(iv, "`%s' is not allowed as a class variable name", RSTRING_PTR(iv));
+	}
+    }
     if (!rb_is_class_id(id)) {
 	rb_name_error(id, "`%s' is not allowed as a class variable name", rb_id2name(id));
     }
@@ -2006,7 +2036,14 @@ rb_mod_cvar_defined(VALUE obj, VALUE iv)
 {
     ID id = rb_check_id(iv);
 
-    if (!id && rb_is_class_name(iv)) return Qfalse;
+    if (!id) {
+	if (rb_is_class_name(iv)) {
+	    return Qfalse;
+	}
+	else {
+	    rb_name_error_str(iv, "`%s' is not allowed as a class variable name", RSTRING_PTR(iv));
+	}
+    }
     if (!rb_is_class_id(id)) {
 	rb_name_error(id, "`%s' is not allowed as a class variable name", rb_id2name(id));
     }