UsePathBase() duplicates route paths

[QuantumToasted]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

After some research and testing to find a way to globally prefix my API routes with /api, I have arrived at the following code:

var apiUrl = app.Configuration["RemotePath:Api"]!;
app.UsePathBase(!string.IsNullOrWhiteSpace(apiUrl) ? apiUrl : null);
app.UseRouting();

This works great, and now a endpoint method mapped to /foo/bar is actually mapped to /api/foo/bar. However...it seems there still exists a mapping for /foo/bar.

Take this example controller in a project I'm working on:

[Route("upload")]
public sealed class UploadController : Controller
{
    [HttpPut("oid/{oid}")]
    public async Task<IActionResult> UploadOid(string oid, [FromBody] LocalFileBlobAdapter.RemoteFileLocation location)
    {
        ...
        return NoContent();
    }
}

In Postman, I am able to make a PUT request to /api/upload/oid/{oid}, and /upload/oid/{oid}.

Expected Behavior

Using UsePathBase() should not preserve the original controller routing configuration (IE, what the routing would be if UsePathBase() had never been called).

Steps To Reproduce

app.UsePathBase("/api");
app.UseRouting();

Then add any applicable controllers. (I am using a Web API template project, so I'm unsure what other code is specific to my project and not just the defaults).

If needed I can create a brand new project and put it on GitHub.

Exceptions (if any)

N/A

.NET Version

7.0.102

Anything else?

JetBrains Rider, project is targeting net7.0. Referenced packages, if of any use:

<ItemGroup>
    <PackageReference Include="Estranged.Lfs.Api" Version="3.1.0" />
    <PackageReference Include="Estranged.Lfs.Authenticator.GitHub" Version="3.1.0" />
    <PackageReference Include="JWT" Version="10.0.2" />
    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="7.0.2" />
    <PackageReference Include="Octokit.Webhooks.AspNetCore" Version="1.4.0" />
    <PackageReference Include="StackExchange.Redis" Version="2.6.104" />
    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
</ItemGroup>

[QuantumToasted]

Woops, I neglected to search through closed issues as well. Seems to be a duplicate of #45076 - it would be nice, if not already the case, to document this behavior, because it doesn't seem intuitive at all to me, that both endpoints function after using this middleware. I will look into what this new 7.0 route groups feature is and hope it can work for my use case.