From: "thyresias (Thierry Lambert) via ruby-core" <ruby-core@...>
Date: 2025-11-24T18:01:59+00:00
Subject: [ruby-core:123896] [Ruby Bug#21709] Inconsistent encoding by Regexp.escape

Issue #21709 has been updated by thyresias (Thierry Lambert).


> Does this behavior cause any problems in your application?

Yes:
```ruby
search_text = "foo"
s_search = Regexp.escape(search_text)
re_prefix = /\p{In_Arabic}.+ /
s_search.prepend re_prefix.source
_re = /^#{s_search}|(?<=��� |: )#{s_search}/ #=> encoding mismatch in dynamic regexp : US-ASCII and UTF-8 (RegexpError)
```



----------------------------------------
Bug #21709: Inconsistent encoding by Regexp.escape
https://bugs.ruby-lang.org/issues/21709#change-115300

* Author: thyresias (Thierry Lambert)
* Status: Feedback
* ruby -v: ruby 3.4.7 (2025-10-08 revision 7a5688e2a2) +PRISM [x64-mingw-ucrt]
* Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN
----------------------------------------
```ruby
%w(foo ��tre).each do |s|
  puts "string: #{s.inspect} -> #{s.encoding}"
  puts "escaped: #{Regexp.escape(s).inspect} -> #{Regexp.escape(s).encoding}"
end
```
Output:
```
string: "foo" -> UTF-8
escaped: "foo" -> US-ASCII
string: "��tre" -> UTF-8
escaped: "��tre" -> UTF-8
```
The result should always match the encoding of the argument.



-- 
https://bugs.ruby-lang.org/
______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/