From: Lazaridis Ilias <ilias@...>
Date: 2011-07-03T01:35:20+09:00
Subject: [ruby-core:37745] [Ruby 1.9 - Bug #4893] Literal Instantiation breaks Object Model


Issue #4893 has been updated by Lazaridis Ilias.

File test_runner_String_initialize.diff added

Lazaridis Ilias wrote:
[...]
> I still need to verify that this draft implementation does not break existent behaviour. If assumed that passing all "make test" is not enough, and indeed "make test-all" uncovered some problems.

Find attached the modification for test/runner.rb in order to run "make test-all".

Five tests failed, all with the same message: "Insecure: can't set class variable."

test_safe_04(TestERBCore):
test_safe_04(TestERBCoreWOStrScan):
test_safe4(TestException) [P:/sand/rubyi2/sandbox/ruby193/test/ruby/test_exception.rb:243]:
test_exec_recursive(TestObject):
test_taint(TestRegexp) [P:/sand/rubyi2/sandbox/ruby193/test/ruby/test_regexp.rb:495]:

Seems to have to do with the "tainted" mechanism, not sure if the access to the class-variable should be disallowed (the class object String is *not* tainted, only it's instances). But that's not the issue, as it's a detail of the test code.

-

I'll move tomorrow on, implementing the final (production) version. Can someone inform me please about this:

* is there a standard mechanism to detect "singleton-method created/deleted", which works on the C-level?



[please note that the UI here does not allow me to reopen an issue by myself].
----------------------------------------
Bug #4893: Literal Instantiation breaks Object Model
http://redmine.ruby-lang.org/issues/4893

Author: Lazaridis Ilias
Status: Rejected
Priority: Normal
Assignee: Yukihiro Matsumoto
Category: 
Target version: 
ruby -v: 1.9.2


#String2.rb 
class String 
  def initialize(val) 
    self.replace(val) 
    puts object_id 
  end 
  def my_method_test 
    'has method <my_method_test>' 
  end 
end 

# command line 
$ irb 
irb(main):001:0> original = String.new("original") 
=> "original" 
irb(main):002:0> load "String2.rb" 
=> true 
irb(main):003:0> altered = String.new("altered") 
21878604 
=> "altered" 
irb(main):004:0> altered.my_method_test 
=> "has method <my_method_test>" 
irb(main):005:0> literal = "literal" 
=> "literal" 
irb(main):006:0> literal.my_method_test 
=> "has method <my_method_test>" 
irb(main):007:0> 

- 

The initialize method is an integral part of the class String. 
From the moment that "String2.rb" is loaded, the initialize method of 
class String has been validly redefined. 

(The behaviour of the String class within the "irb session" is 
altered) 

The altered initialize method is now an integral part of the class 
String. 

The altered String object behaves as expected (responds to 
"my_method_test, initialized via redefined initialize method). 

The String(Literal) object responds to "my_method_test", but it is was 
not initialized with the redefined initialize method. 

- 

The "Literal Instantiation" calls the original (core-C-level) String 
initialize method instead of the redefined one (user-language-level). 
This *breaks* the object model. 





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