Issue #17400 has been updated by katiecaballero2023 (Katie Caballero). RubyConf Hack Day: Bug still exists in 3.2.2 ---------------------------------------- Bug #17400: Incorrect character downcase for Greek Sigma https://bugs.ruby-lang.org/issues/17400#change-105308 * Author: xfalcox (Rafael Silva) * Status: Open * Priority: Normal * Assignee: duerst (Martin Dürst) * ruby -v: ruby 3.0.0dev (2020-12-16T18:46:44Z master 93ba3ac036) [x86_64-linux] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- An issue caused by this bug was first reported at Discourse support community at https://meta.discourse.org/t/unicode-username-results-in-error-loading-profi.... The issue is that in Greek, there are two ways to downcase the letter ‘Σ’ - ‘ς’ when it is used at the end of a word - ‘σ’ anywhere else NodeJS follows this rule: ``` ➜ node Welcome to Node.js v12.11.1. Type ".help" for more information.

"ΣΠΥΡΟΣ".toLowerCase() 'σπυρος'

Python too:

➜ python Python 3.8.2 (default, Nov 23 2020, 16:33:30) [GCC 10.2.0] on linux Type "help", "copyright", "credits" or "license" for more information.

...

...

"ΣΠΥΡΟΣ".lower() 'σπυρος'

Ruby (both 2.7 and 3) doesn't:

➜ ruby --version ruby 3.0.0dev (2020-12-16T18:46:44Z master 93ba3ac036) [x86_64-linux] ➜ irb irb(main):001:0> "ΣΠΥΡΟΣ".downcase => "σπυροσ" ``` ``` ➜ ruby --version ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-linux] ➜ irb irb(main):001:0> "ΣΠΥΡΟΣ".downcase => "σπυροσ" ``` -- https://bugs.ruby-lang.org/