error.c: rb_check_copyable

* error.c (rb_check_copyable): new function, to ensure the target is
  not frozen and the source is not tainted nor untrusted.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36174 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Fri Jun 22 13:32:33 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* error.c (rb_check_copyable): new function, to ensure the target is
+	  not frozen and the source is not tainted nor untrusted.
+
 Fri Jun 22 05:55:20 2012  Eric Hodel  <drbrain@segment7.net>
 
 	* eval.c (ruby_cleanup):  Fixed typo.  Patch by Trever Dawe.

error.c

@@ -2010,6 +2010,21 @@ rb_check_trusted(VALUE obj)
     rb_check_trusted_internal(obj);
 }
 
+void
+rb_check_copyable(VALUE obj, VALUE orig)
+{
+    if (!FL_ABLE(obj)) return;
+    rb_check_frozen_internal(obj);
+    rb_check_trusted_internal(obj);
+    if (!FL_ABLE(orig)) return;
+    if ((~RBASIC(obj)->flags & RBASIC(orig)->flags) & (FL_UNTRUSTED|FL_TAINT)) {
+	if (rb_safe_level() > 0) {
+	    rb_raise(rb_eSecurityError, "Insecure: can't modify %"PRIsVALUE,
+		     RBASIC(obj)->klass);
+	}
+    }
+}
+
 void
 Init_syserr(void)
 {

include/ruby/intern.h

@@ -251,6 +251,7 @@ rb_check_trusted_inline(VALUE obj)
 }
 #define rb_check_trusted(obj) rb_check_trusted_inline(obj)
 #endif
+void rb_check_copyable(VALUE obj, VALUE orig);
 
 #define OBJ_INIT_COPY(obj, orig) \
     ((obj) != (orig) && (rb_obj_init_copy((obj), (orig)), 1))