Can not create RSA-Key, Access Denied, Special Characters in Usernames

[Buedenbender]

System details

RStudio Edition : Desktop 
RStudio Version : 1.4.1717
OS Version      :  Windows 10 Pro (64bit)
R Version       :  4.1.1

Steps to reproduce the problem

1. Have special character in your username (e.g. ö or é)
2. Start Rstudio -> Tools -> Global Options
3. Go to GiT / SVN
4. Click "Create RSA Key ..."

Describe the problem in detail

I can not create an RSA-Key from RStudio. It fails with the message "Access denied" (Translated from German [Zugriff verweigert], see Screenshot 1), this is not surprising as the path were the key is supposed to be created contains special characters. Which are not supported (see Screenshot 2). Screenshot 1 Screenshot 2

Describe the behavior you expected

Ability to create the RSA-Key within Rstudio.

• [X] I have read the guide for submitting good bug reports.
• [X] I have installed the latest version of RStudio, and confirmed that the issue still persists.
• [x] If I am reporting an RStudio crash, I have included a diagnostics report.
• [X] I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.

On a sidenote special characters seem to generally cause problem when working with rstudio for example for addins as well. Of course I would prefer to have no special characters in my user name (or even better use linux) however sometimes you dont have a choice and you got to work with the account / setup handed to you. TL;DR I can not change my username

[ronblum]

@Buedenbender Thank you for raising this! FWIW, we've run into issues in the past with special characters in other areas. I'll mark it for review as we continue to develop RStudio.