From: nobu@...
Date: 2017-06-30T05:06:40+00:00
Subject: [ruby-core:81843] [Ruby trunk Bug#13698][Rejected] Sort Methods	Differ

Issue #13698 has been updated by nobu (Nobuyoshi Nakada).

Description updated
Status changed from Open to Rejected

`Array#sort` is not guaranteed as "stable".
You should compare other keys if they matter.

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Bug #13698: Sort Methods Differ
https://bugs.ruby-lang.org/issues/13698#change-65559

* Author: sherrysarkar (Sherry  Sarkar)
* Status: Rejected
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: ruby 2.3.3p222 (2016-11-21 revision 56859)
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
Hello,

### Issue:
Two different machines with the same ruby version return different results for the method "sort". One machine runs macOS and the other runs Linux. More specifically, when I run "ruby --version" in the macOS machine, I get "ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-darwin16]" and when I run "ruby --version" in the Linux machine, I get "ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-linux]".

### Reproducibility:
If you run the following script in the two machines described above, you get different results. 

~~~
arr  = [{"id"=>"549741245", "changed"=>"2015-06-24T22:02:51Z"},
 {"id"=>"549760170", "changed"=>"2015-06-24T23:15:44Z"}, 
 {"id"=>"549760171", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549760172", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"551080187", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"551080188", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"551080189", "changed"=>"2015-06-29T21:49:24Z"}]
arr.sort { |a, b| b['changed'] <=> a['changed'] }
~~~
**Results** 
The macOS machine returns

~~~ ruby
[{"id"=>"551080189", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"551080187", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"551080188", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"549760172", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549760170", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549760171", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549741245", "changed"=>"2015-06-24T22:02:51Z"}]
~~~
The Linux machine returns

~~~ ruby
[{"id"=>"551080187", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"551080188", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"551080189", "changed"=>"2015-06-29T21:49:24Z"},
 {"id"=>"549760170", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549760171", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549760172", "changed"=>"2015-06-24T23:15:44Z"},
 {"id"=>"549741245", "changed"=>"2015-06-24T22:02:51Z"}]
~~~
I would expect for sort (ruby 2.3.3p222) to return the same results given the same input.

Thanks!
 



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