# \[ruby-trunk - Bug #10393\] \[Open\] String#start\_with?の1.9.x非互換バグ

**URL:** <https://www.ruby-forum.com/t/ruby-trunk-bug-10393-open-string-start-with-1-9-x/232572>\
**Category:** Development\
**Created:** [October 16, 2014, 12:12pm UTC](https://www.ruby-forum.com/t/ruby-trunk-bug-10393-open-string-start-with-1-9-x/232572 "2014-10-16T12:12:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [October 16, 2014, 12:12pm UTC](https://www.ruby-forum.com/t/ruby-trunk-bug-10393-open-string-start-with-1-9-x/232572/1 "2014-10-16T12:12:56Z")

</div>

Issue #10393 has been reported by Hideyuki Matsuyama.

* * *

Bug #10393: String#start\_with?の1.9.x非互換バグ

> **[Bug #10393: String#start\_with?の1.9.x非互換バグ - Ruby master - Ruby Issue Tracking...](https://bugs.ruby-lang.org/issues/10393)**
>
> Redmine

- Author: Hideyuki Matsuyama
- Status: Open
- Priority: Normal
- Assignee:
- Category:
- Target version:
- ruby -v: ruby 2.1.3p242 (2014-09-19 revision 47630)  
[x86\_64-darwin13.0]
- Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN

* * *

```auto
$ ruby -v
ruby 1.9.3p547 (2014-05-14 revision 45962) [x86_64-darwin13.4.0]
$ irb
> 'foo'.start_with? nil
 => false

```

```auto
$ ruby -v
ruby 2.1.3p242 (2014-09-19 revision 47630) [x86_64-darwin13.0]
$ irb
> 'foo'.start_with? nil
TypeError: no implicit conversion of nil into String

```

バージョン1.9系との互換性を保つため、結果がfalseになることを期待します。