Blazor hosted project with static folder in different cases

[CrahunGit]

Describe the bug

In Blazor webassembly hosted project, if the client side has a folder with lowercase name and the server side has a static uppercase folder name the project will fail on runtime saying System.ArgumentException: 'An item with the same key has already been added. Key: Img'

It worked fine on preview 6 an earlier.

To Reproduce

I've uploaded a repo with this issue. Just need to execute the server project.
https://github.com/CrahunGit/BlazorStaticUppercaseFolders

We will close this issue if:
The case should not be taken account on static folders. It just should be need to merge their contents.

Exceptions (if any)

System.ArgumentException: 'An item with the same key has already been added. Key: Img'

Further technical details

• ASP.NET Core version 6 preview 7
• Include the output of dotnet --info
  SDK de .NET (que refleje cualquier global.json):
  Version: 6.0.100-preview.7.21379.14
  Commit: 22d70b47bc

Entorno de tiempo de ejecución:
OS Name: Windows
OS Version: 10.0.19043
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\6.0.100-preview.7.21379.14\

Host (useful for support):
Version: 6.0.0-preview.7.21377.19
Commit: 91ba01788d

.NET SDKs installed:
2.2.207 [C:\Program Files\dotnet\sdk]
3.0.103 [C:\Program Files\dotnet\sdk]
3.1.405 [C:\Program Files\dotnet\sdk]
5.0.201 [C:\Program Files\dotnet\sdk]
5.0.202 [C:\Program Files\dotnet\sdk]
5.0.300-preview.21180.15 [C:\Program Files\dotnet\sdk]
5.0.400 [C:\Program Files\dotnet\sdk]
6.0.100-preview.7.21379.14 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.26 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.29 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.26 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.29 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.18 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.0-preview.7.21378.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.29 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.18 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.0-preview.5.21301.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.0-preview.7.21377.19 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.18 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.0-preview.5.21301.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.0-preview.7.21378.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

• The IDE (VS / VS Code/ VS4Mac) you're running on, and its version
  Visual studio 2022 Version 17.0.0 Preview 3.0

[javiercn]

@CrahunGit thanks for contacting us.

I'm not able to access the repro project.

[CrahunGit]

Sorry. It was my mistake. It's public now.

[javiercn]

The bug is here:
https://github.com/dotnet/aspnetcore/blob/main/src/Hosting/Hosting/src/StaticWebAssets/StaticWebAssetsFileProvider.cs#L513-L515

We always produce the manifest with case-sensitive entries (as we should), however on Windows we should fuse entries with different casing into the same node at runtime.

This is just a matter of iterating over the dictionary and checking if the key already exists before we add it. We want the manifest to keep the full details about the casing for when we are running in Docker containers from within Windows.