[ruby-core:94737] [Ruby master Bug#15244] Method #extname return empty string if filename is dot ('.')

[zn@mbf.nifty.com]

Issue #15244 has been updated by znz (Kazuhiro NISHIYAMA).


In some other languages:

```
% python
Python 2.7.16 (default, Mar  4 2019, 09:01:38)
[GCC 4.2.1 Compatible Apple LLVM 10.0.0 (clang-1000.11.45.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.splitext('..jpg')
('..jpg', '')
```

```
% python3
Python 3.7.4 (default, Jul  9 2019, 18:13:23)
[Clang 10.0.1 (clang-1001.0.46.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.splitext('..jpg')
('..jpg', '')
```

```
% php --version
PHP 7.1.23 (cli) (built: Feb 22 2019 22:19:32) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies
% php -r 'var_export(pathinfo("..jpg", PATHINFO_EXTENSION));'
'jpg'
```

ref https://hydrocul.github.io/wiki/programming_languages_diff/io/extname.html

----------------------------------------
Bug #15244: Method #extname return empty string if filename is dot ('.')
https://bugs.ruby-lang.org/issues/15244#change-81355

* Author: TiSer (Sergey TiSer)
* Status: Feedback
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 2.7.0dev
* Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN
----------------------------------------
### Example 1:
Current behaviour:
```
File.extname('..jpg')
=> ""
```

Expected behaviour: 
```
File.extname('..jpg')
=> ".jpg"
```


### Example 2:
Current behaviour:
```
File.extname('....jpg')
=> ""
```

Expected behaviour: 
```
=> ".jpg"
```

---Files--------------------------------
dot-names.diff (891 Bytes)
multiple-leading-dot-basename-extname-15244.patch (1.94 KB)


-- 
https://bugs.ruby-lang.org/