Runtime: Assembly.CodeBase does not produce a correctly escaped URI

[archanasoni]

Hi,

We have a customer case where their Application path contains '#'.
For example path is:
C:/Users/asoni/source/repos/Demo#App/DemoApp
and we get path for IBM.Data.DB2.Core.dll using below code:
typeof(DB2Connection).Assembly.CodeBase

Output is:

file:///C:/Users/asoni/source/repos/Demo#App/DemoApp/bin/Debug/netcoreapp3.1/IBM.Data.DB2.Core.dll

Now we use Uri class to get physical path:
string assemLoc = (new Uri(typeof(DB2Connection).Assembly.CodeBase)).LocalPath;

Output is:

C:\Users\asoni\source\repos\Demo

Expected output:

C:/Users/asoni/source/repos/Demo#App/DemoApp/bin/Debug/netcoreapp3.1/IBM.Data.DB2.Core.dll

If we don't have # in Application path it works perfectly fine..

Could you share what is the reason behind this behavior and How come we can overcome this issue if we want to allow # in path ?

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[scalablecory]

Doesn't appear to be an issue with Uri itself. Can you share a minimal repro?

I tried:
```c#
var u = new Uri("C:/Users/asoni/source/repos/Demo#App/DemoApp/bin/Debug/netcoreapp3.1/IBM.Data.DB2.Core.dll");
Console.WriteLine(u);
Console.WriteLine(u.LocalPath);

Which outputs:

file:///C:/Users/asoni/source/repos/Demo%23App/DemoApp/bin/Debug/netcoreapp3.1/IBM.Data.DB2.Core.dll
C:\Users\asoni\source\repos\Demo#App\DemoApp\bin\Debug\netcoreapp3.1\IBM.Data.DB2.Core.dll
```

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[scalablecory]

@marcpopMSFT did you mean to self-assign this one?

[marcpopMSFT]

@scalablecory it was assigned to me in the sdk repo for triage and I forgot to unassign when transferring over

[archanasoni]

@scalablecory here is repro:

var u = new Uri("file:///C:/Users/asoni/source/repos/Demo#App/DemoApp/bin/Debug/netcoreapp3.1/IBM.Data.DB2.Core.dll");
            Console.WriteLine(u);
            Console.WriteLine(u.LocalPath);

Output:

file:///C:/Users/asoni/source/repos/Demo#App/DemoApp/bin/Debug/netcoreapp3.1/IBM.Data.DB2.Core.dll
C:\Users\asoni\source\repos\Demo

[MihaZupan]

Uri will parse the # in file:///C:/Users/foo#App/bar.dll as a fragment.
If # is meant as a character belonging to the file path, it should be escaped: file:///C:/Users/foo%23App/bar.dll.

Uri will correctly escape the # when you retrieve the absolute Uri:
new Uri("C:/Users/foo#App/bar.dll").AbsoluteUri => file:///C:/Users/foo%23App/bar.dll

So I would argue that the problem here is not with Uri, but Assembly.CodeBase.
Seeing as https://github.com/dotnet/runtime/issues/31127#issuecomment-545084027 is approved, making CodeBase both obsolete and [EditorBrowsable(Never)], the customer should switch to using Assembly.Location.

Assembly.Location outputs the file path without the explicit file scheme, so the # is not treated as a fragment if used in Uri.
new Uri(typeof(Program).Assembly.Location).LocalPath