Issue #6190 has been updated by zzak (Zachary Scott). Assignee set to naruse (Yui NARUSE) naruse-san what do you want for this ticket? ---------------------------------------- Backport #6190: String#encode return string containing invalid chars but marked as valid https://bugs.ruby-lang.org/issues/6190#change-36835 Author: pplr (Pierre PLR) Status: Assigned Priority: Normal Assignee: naruse (Yui NARUSE) Category: Target version: >> a = " \xE9 ".encode('UTF-8', 'UTF-8', :invalid => :replace, :replace => "?") >> a.valid_encoding? => true >> a => " \xE9 " >> a.squeeze ArgumentError: invalid byte sequence in UTF-8 from (irb):32:in `squeeze' from (irb):32 from /usr/bin/irb:12:in `<main>' The expected string is " ? ", as the documentation for the ":replace" options says : If the value is :replace, encode replaces invalid byte sequences in str with the replacement character. -- http://bugs.ruby-lang.org/