From: duerst via ruby-core <ruby-core@...>
Date: 2023-07-26T09:25:15+00:00
Subject: [ruby-core:114294] [Ruby master Bug#19784] String#delete_prefix! problem

Issue #19784 has been updated by duerst (Martin D�rst).





I agree that `start_with?` and `delete_prefix!` should probably be aligned. But in general, encoding problems should lead to early errors, not be deferred.



----------------------------------------

Bug #19784: String#delete_prefix! problem

https://bugs.ruby-lang.org/issues/19784#change-103992



* Author: inversion (Yura Babak)

* Status: Open

* Priority: Normal

* ruby -v: ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux]

* Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN

----------------------------------------

Here is the snipped and the question is in the comments:

``` ruby

fp = 'with_BOM_16.txt'

body = File.read(fp).force_encoding('UTF-8')



p body                            # "\xFF\xFE1\u00001\u0000"

p body.start_with?("\xFF\xFE")    # true



body.delete_prefix!("\xFF\xFE")   # !!! why doesn't work?

p body                            # "\xFF\xFE1\u00001\u0000"

p body.start_with?("\xFF\xFE")    # true



body[0, 2] = ''

p body                            # "1\u00001\u0000"

p body.start_with?("\xFF\xFE")    # false



```

Works same 

on Linux (ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux])

and Windows (ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x64-mingw-ucrt])







-- 

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/postorius/lists/ruby-core.ml.ruby-lang.org/