From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from neon.ruby-lang.org (neon.ruby-lang.org [221.186.184.75]) by dcvr.yhbt.net (Postfix) with ESMTP id 4BC111F5AE for ; Fri, 24 Jul 2020 17:52:58 +0000 (UTC) Received: from neon.ruby-lang.org (localhost [IPv6:::1]) by neon.ruby-lang.org (Postfix) with ESMTP id 35D3A1209C5; Sat, 25 Jul 2020 02:52:25 +0900 (JST) Received: from xtrwkhkc.outbound-mail.sendgrid.net (xtrwkhkc.outbound-mail.sendgrid.net [167.89.16.28]) by neon.ruby-lang.org (Postfix) with ESMTPS id D80261209B5 for ; Sat, 25 Jul 2020 02:52:22 +0900 (JST) Received: by filterdrecv-p3iad2-5b55dcd864-84x54 with SMTP id filterdrecv-p3iad2-5b55dcd864-84x54-18-5F1B1FF2-5 2020-07-24 17:52:50.086244452 +0000 UTC m=+2421801.350171774 Received: from herokuapp.com (unknown) by ismtpd0053p1iad1.sendgrid.net (SG) with ESMTP id AETYJyttSQ6Q3btE3s3ktg for ; Fri, 24 Jul 2020 17:52:49.939 +0000 (UTC) Date: Fri, 24 Jul 2020 17:52:50 +0000 (UTC) From: merch-redmine@jeremyevans.net Message-ID: References: Mime-Version: 1.0 X-Redmine-MailingListIntegration-Message-Ids: 75105 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Bug X-Redmine-Issue-Id: 17048 X-Redmine-Issue-Author: alanwu X-Redmine-Sender: jeremyevans0 X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-SG-EID: =?us-ascii?Q?RVE3t853K5scBhbmJHUzZTFFeVC=2FZSUmHZ0Dc+26wcEi2CTgsF1oz0wTSSxGGN?= =?us-ascii?Q?BIo778gs3Xtjlw9=2F9j1JzIttLRfXEethRDtXNRA?= =?us-ascii?Q?jXSGkXpEewy7D0vIa=2Fmz+xPTMJALvnSLGs+mP+s?= =?us-ascii?Q?jE39v7qY5DYyB1BOTXcHdj95NTh4Ian6EuS+xRc?= =?us-ascii?Q?CwHd5uJtlWZzGw+T9mY8ATvEBv0GhDJYRSzYqAz?= =?us-ascii?Q?x3gnIWqAvJc7u70jI=3D?= To: ruby-core@ruby-lang.org X-ML-Name: ruby-core X-Mail-Count: 99314 Subject: [ruby-core:99314] [Ruby master Bug#17048] Calling initialize_copy on live modules leads to crashes X-BeenThere: ruby-core@ruby-lang.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: Ruby developers List-Id: Ruby developers List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ruby-core-bounces@ruby-lang.org Sender: "ruby-core" Issue #17048 has been updated by jeremyevans0 (Jeremy Evans). I would recommend to have `initialize_copy` always raise instead of only raising if the module has children. It's more consistent, and there is no reason anyone should be calling `initialize_copy` more than once. This shouldn't be considered a breaking change, as `initialize_copy` is a private method. I think it is better than moving the logic to `dup`/`clone`, just in case a Module subclass is overridding `initialize_copy` and calling super. ---------------------------------------- Bug #17048: Calling initialize_copy on live modules leads to crashes https://bugs.ruby-lang.org/issues/17048#change-86708 * Author: alanwu (Alan Wu) * Status: Open * Priority: Normal * ruby -v: ruby 2.8.0dev (2020-07-23T14:44:25Z master 098e8c2873) [x86_64-linux] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- Here's a repro script ```ruby loop do m = Module.new do prepend Module.new def hello end end klass = Class.new { include m } m.send(:initialize_copy, Module.new) GC.start klass.new.hello rescue nil end ``` Here's a script that shows that it has broken semantics even when it happens to not crash. ```ruby module A end class B include A end module C Const = :C end module D Const = :D end A.send(:initialize_copy, C) p B::Const # :C, makes sense A.send(:initialize_copy, D) p B::Const # :D, makes sense A.send(:initialize_copy, Module.new) p (begin B::Const rescue NameError; 'NameError' end) # NameError, makes sense A.send(:initialize_copy, C) p B::Const # still NameErorr. Weird ``` This example shows that the problem exists [as far back as 2.0.0](https://wandbox.org/permlink/4dVDY9sNXJ803jh8). I think the easiest way to fix this is to forbid calling `:initialize_copy` on modules that have children. Another option is to try to decide on the semantics of this. Though I don't think it's worth the effort as this has been broken for a long time and people don't seem to to be using it. Thoughts? -- https://bugs.ruby-lang.org/