[ruby-core:94332] [Ruby master Bug#15244] Method #extname return empty string if filename is dot ('.')

Issue #15244 has been updated by jeremyevans0 (Jeremy Evans).

File multiple-leading-dot-basename-extname-15244.patch added

I agree that this is a bug.  The comparison that nobu made with `basename(1)` is relevant, but unlike `File.basename`, `basename(1)` does not handle `.*` specially.  You can see that `basename(1)` does actually strip the extension even for multiple leading periods:

```
basename '..*' '.*'
..
```

Attached is a patch that fixes the issue, both for `File.basename` and `File.extname`.  With the patch:

```ruby
File.basename('..jpg', '.*')
# => "."
File.extname('..jpg')
# => ".jpg"
```

----------------------------------------
Bug #15244: Method #extname return empty string if filename is dot ('.')
https://bugs.ruby-lang.org/issues/15244#change-80724

* Author: TiSer (Sergey TiSer)
* Status: Open
* 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/

Unsubscribe: <mailto:[e-mail]?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>