Issue #19441 has been updated by stac47 (Laurent Stacul). Provided `#dup` generally returns an object of the same type, I would expect to have a `Tempfile` object. The unexpected thing was that if I replay the same scenario with `File`, I have what I expect. I was just wondering whether the behaviour discrepancy between `File` and `Tempfile` was normal. ```ruby irb(main):001:0> file = File.new("a_file.txt", "w+") => #<File:a_file.txt> irb(main):002:0> file.size => 0 irb(main):003:0> dup = file.dup => #<File:a_file.txt> irb(main):004:0> dup.closed? => false irb(main):005:0> file.closed? => false irb(main):006:0> dup.close => nil irb(main):007:0> dup.closed? => true irb(main):008:0> file.closed? => false ``` ---------------------------------------- Bug #19441: Closing an IO#dup behaviour https://bugs.ruby-lang.org/issues/19441#change-101896 * Author: stac47 (Laurent Stacul) * Status: Open * Priority: Normal * ruby -v: ruby 3.2.1 (2023-02-08 revision 31819e82c8) [x86_64-darwin20] * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- Hello amazing ruby folks! I classified that ticket as a "Bug" although it is perhaps something I did not understand. Here is a ruby session: ``` ruby irb(main):001:0> file = Tempfile.new => #<File:/var/folders/m2/bljzrgq160vbf0vk466k_7gw0000gn/T/20230216-39664-davfmj> irb(main):002:0> file.fileno => 9 irb(main):003:0> dup = file.dup => #<File:/var/folders/m2/bljzrgq160vbf0vk466k_7gw0000gn/T/20230216-39664-davfmj> irb(main):004:0> dup.fileno => 10 irb(main):005:0> dup.close => nil irb(main):006:0> dup.closed? => false irb(main):007:0> file.closed? => true ``` The two last lines are unexpected to me. I would have expected the converse: ```ruby irb(main):006:0> dup.closed? => true irb(main):007:0> file.closed? => false ``` I tried this scenario in latest ruby but also in ruby 2.7. Thanks in advance for helping me to understand this behaviour. -- https://bugs.ruby-lang.org/