httpclient Content.Headers.ContentDisposition.FileName returns null when the file name has space in it

[jayeshchedambath]

Describe the bug

When we receive an http response using httpclient that contains an attachment with content-disposition header and the file name in the header has space in it, the Content.Headers.ContentDisposition.FileName property returns null

To Reproduce

using .Net httpclient read an httpresponse containing a file attachment and content-disposition header, make sure the file name has space in it and file name is not wrapped inside double quoutes.

Exceptions (if any)

Further technical details

• ASP.NET Core version:
• The IDE (VS / VS Code/ VS4Mac) you're running on, and its version:
• Include the output of dotnet --info:

dotnet --info Output

[Tratcher]

Can you provide an example content-disposition header? Your description sounds like an invalid header.

[jayeshchedambath]

Can you provide an example content-disposition header? Your description sounds like an invalid header.

@Tratcher please find below the response header received using POSTMAN , the same response in http client returns null in the file name.
content-disposition :attachment; filename = Defend Your Digital Business From Cyberattacks Using Forrester's Zero Trust Model.pdf

I also observed when I tried to add file name with space like below the add header is also not successful

var firstResponseMessage = new HttpResponseMessage
{
StatusCode = HttpStatusCode.OK,
Content = new StringContent(JsonConvert.SerializeObject("xyz"
), Encoding.UTF8, "application/json")
};
firstResponseMessage.Content.Headers.Add("content-disposition", "attachment; filename = myfile 1.pdf");

it succeeds when i add double quoutes around file name
var firstResponseMessage = new HttpResponseMessage
{
StatusCode = HttpStatusCode.OK,
Content = new StringContent(JsonConvert.SerializeObject("xyz"
), Encoding.UTF8, "application/json")
};
firstResponseMessage.Content.Headers.Add("content-disposition", "attachment; filename = \"myfile 1.pdf\"");

[Tratcher]

This all seems like standard header behavior, values with spaces require quotes.

[jayeshchedambath]

makes sense and i confirmed this with RFC too, if this is a non standard header value an exception to consumer while trying to add this header value or read the filename property would be appropriate ?

[jayeshchedambath]

closing this issue as is this a known behavior as per RFC