[ruby-core:116231] [Ruby master Bug#20189] `rb_str_resize` does not clear coderange when expanding

Issue #20189 has been updated by byroot (Jean Boussier).


> Expanding string in some encoding (utf16 utf32) can change coderange to either valid or broken,

I must admit I'm not very familiar with wide char encodings, but this surprises me a bit. Ruby strings should always have their terminator, so I don't see how expanding a string would change their interpretation.

----------------------------------------
Bug #20189: `rb_str_resize` does not clear coderange when expanding
https://bugs.ruby-lang.org/issues/20189#change-106250

* Author: tompng (tomoya ishida)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.4.0dev (2024-01-09T07:07:19Z master db476cc71c) [x86_64-linux]
* Backport: 3.0: DONTNEED, 3.1: DONTNEED, 3.2: REQUIRED, 3.3: REQUIRED
----------------------------------------
Expanding string in some encoding (utf16 utf32) can change coderange to either valid or broken, but rb_str_resize does not clear coderange.


This will cause a bug in c-extension libraries that use rb_str_resize.
~~~ruby
# Example for stringio
s = StringIO.new("\0".encode('UTF-16LE'))

s.truncate(1); s.truncate(2); s.string.valid_encoding?
#=> true
s.truncate(1); s.string.valid_encoding?; s.truncate(2); s.string.valid_encoding?
#=> false (expect to be true)
~~~




-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- [e-mail]
 To unsubscribe send an email to [e-mail]
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/