Download filename is truncated if attachment filename contains a #

[VivaLosDoyers]

If the filename of a file attached to a work item contains a #, when a user downloads the file, their browser will download it with the filename truncated to exclude everything from the # and after.

For example, if you upload a file called “Issue #14.docx”, the downloaded file will have the filename "Issue ".

To reproduce:

1. Create a file with a # in the name. For example: Issue Cannot see the extension at all #14.docx
2. Create a work item in Azure DevOps and attach the file to the work item
3. Open the work item and double-click the attachment to download
4. Expected: The attachment should have the original filename
5. Actual: The attachment name is truncated, and downloaded as "Issue "

This has been reproduced in both Chrome 90 and Edge 90