[ruby-core:97950] [Ruby master Bug#16798] ENV.replace on Windows with a variable name not respecting case will clear it

Issue #16798 has been updated by deivid (David Rodr刕uez).


Thanks for the quick fix @nobu, and for setting the backports! <3

----------------------------------------
Bug #16798: ENV.replace on Windows with a variable name not respecting case will clear it
https://bugs.ruby-lang.org/issues/16798#change-85176

* Author: deivid (David Rodr刕uez)
* Status: Closed
* Priority: Normal
* Backport: 2.5: REQUIRED, 2.6: REQUIRED, 2.7: REQUIRED
----------------------------------------
On Windows, environment variable names are case insensitive:

```
PS C:\Users\deivi> ruby -e "puts ENV['Path']; ENV['PATH'] = 'foo'; puts ENV['Path']"                                                                                                                                                     C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Ruby26-x64\bin;C:\Ruby25-x64\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Ruby27-x64\bin;C:\Ruby25-x64\bin
foo

PS C:\Users\deivi> ruby -e "puts ENV['Path']; ENV.update('PATH' => 'foo'); puts ENV['Path']"                                                                                                                                             C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Ruby26-x64\bin;C:\Ruby25-x64\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Ruby27-x64\bin;C:\Ruby25-x64\bin
foo
```

However, with `ENV.replace`, if you don't use the "canonical casing" (as given by `ENV.keys`, for example), the environment variable will be cleared.

```
PS C:\Users\deivi> ruby -e "puts ENV['Path']; ENV.replace('PATH' => 'foo'); puts ENV['Path']"                                                                                                                                                 C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Ruby26-x64\bin;C:\Ruby25-x64\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Ruby27-x64\bin;C:\Ruby25-x64\bin


```

This is unexpected to me.



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

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