Issue #21559 has been updated by duerst (Martin Dürst). Status changed from Open to Closed Added regression test at https://github.com/ruby/ruby/commit/a122d7a58e91ed6cd531e906cb398688d7cc8b17 and fix at https://github.com/ruby/ruby/commit/e4c8e3544237b8c0efba6b945173dc66552d641c. Many thanks to Tomoya Ishida for finding this bug. ---------------------------------------- Bug #21559: Unicode normalization nfd -> nfc -> nfd is not reversible https://bugs.ruby-lang.org/issues/21559#change-115023 * Author: tompng (tomoya ishida) * Status: Closed * Assignee: duerst (Martin Dürst) * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- I expect `nfd(nfc(str)) == nfd(str)` but found a string that doesn't. ~~~ruby # Ruby 3.1 - 3.5 str = "s\u{11930}\u{323}\u{11930}\u{307}" p str.unicode_normalize(:nfd) == str.unicode_normalize(:nfc).unicode_normalize(:nfd) #=> false ~~~ ~~~ruby # ruby 3.5.0dev str = "s\u{1611e}\u{323}\u{1611e}\u{307}\u{1611f}" p str.unicode_normalize(:nfd) == str.unicode_normalize(:nfc).unicode_normalize(:nfd) #=> false ~~~ -- https://bugs.ruby-lang.org/