Uploaded file has incorrectly encoded filename if this filename has non-ASCII characters

[inna-artiushenko]

Describe the bug
If you try to upload a file that has non-ASCII characters in its filename (eg. ÄÖäö.jpg), then Content-Disposition is encoded to smth like "=?utf-8?B?S29hbGHDhMOWw6TDti5qcGc=?="

To Reproduce

1. Set a breakpoint to https://github.com/restsharp/RestSharp/blob/dev/src/RestSharp/Request/RequestContent.cs#L65
2. Rename test file Koala.jpg to KoalaÄÖäö.jpg
3. Change test data (to filename = "KoalaÄÖäö.jpg") and run an upload test eg. Should_upload_from_file
4. Check fileContent.Headers.ContentDisposition value in RequestContent.AddFiles()

Expected behavior
fileContent.Headers.ContentDisposition - form-data; name="file"; filename="ÄÖäö.jpg"

Actual behavior
fileContent.Headers.ContentDisposition - form-data; name="file"; filename="=?utf-8?B?S29hbGHDhMOWw6TDti5qcGc=?="

Notes
For a file like Koala.jpg fileContent.Headers.ContentDisposition is form-data; name="file"; filename="Koala.jpg".
Initially, it's an issue with ContentDispositionHeaderValue (microsoft/referencesource#140), but I don't know how to fix it there.

[asynchk]

Thanks for raising the issue I am facing the same problem

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[repo-ranger]

⚠️ This issue has been marked wontfix and will be closed in 3 days

[PooraniPerumal]

I am facing the same issue.

[alexeyzimarev]

I'd like to know more about the issue itself. Why is the current behaviour wrong? We have an integrated test that sends the file to an echo upload API, and it works with both ASCII and non-ASCII characters. Do you have a specific server that for some reason is unable to understand web standards?

[PooraniPerumal]

I was not sure that this was the expected behaviour. I was thinking that something was wrong with my code because when the same file is uploaded via postman client to the server, the filename is preserved with its foreign characters.

…

On Thu, Jul 7, 2022 at 6:27 PM Alexey Zimarev ***@***.***> wrote: I'd like to know more about the issue itself. Why is the current behaviour wrong? We have an integrated test that sends the file to an echo upload API, and it works with both ASCII and non-ASCII characters. Do you have a specific server that for some reason is unable to understand web standards? — Reply to this email directly, view it on GitHub <#1828 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANV5QQEV3MMBLZKQVYZ6F7LVS3H2DANCNFSM5SQXF63A> . You are receiving this because you commented.Message ID: ***@***.***>

-- *Regards,* *Poorani.*

[alexeyzimarev]

Normally, the server should be able to decide the MIME-encoded filename. The current implementation, however, doesn't support the filename* parameter, which is the UTF-8 encoded filename. It worked before. I think the reason for using the current code is that the default values aren't enclosed in quotes and it broke some other servers.

I wish that people who develop servers spend some time reading the docs about how this all should work... Checking some other things now.

[alexeyzimarev]

Ok, I am sorry to say but your code doesn't work. I will create another PR. When I made it work as you expected it to work (without encoding), the tests fail as the ASP.NET Core WebAPI doesn't like it. These tests only passed because your code didn't work. What you got, in fact, is the filename* parameter in the header, which is currently disabled by default.