[Problem/Bug]: ShowSaveAsUI don't work with custom scheme

[jls28]

What happened?

I am using a custom scheme to display a simple html page via
WebResourceRequested/IStream/CreateWebResourceResponse/put_Response.

The first problem : the "Save as" command is not available from the context menu
(same thing happen with the webview2APIsample -> scenario navigate to custom scheme via webResourceRequested).

Second problem : ShowSaveAsUI create a file BUT immediatly delete it
(same thing happen with the webview2APIsample -> navigate to custom scheme via webResourceRequested).

Importance

Moderate. My app's user experience is affected, but still usable.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

134.0.3124.93

SDK Version

1.0.2739.15

Framework

Win32

Operating System

Windows 10

OS Version

19045.4412

Repro steps

webview2APIsample -> navigate to custom scheme via webResourceRequested

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

No, this never worked

Last working version (if regression)

No response

[ParadoxZero]

@jls28 Please share a minimal example to understand the problem.

[jls28]

@ParadoxZero
The problem is that I use a custom scheme
to display an internal generated html page
and I would like save the page to a file
but it is impossible because ShowSaveAsUI
don't work and the "Save as" command is not
available from the context menu.

It is similar to the Microsoft webview2APIsample -> scenario navigate to custom scheme via webResourceRequested :

step 1 : goto Scenario "navigate to custom scheme via webResourceRequested"
this goto the page "wv2rocks://domain/ScenarioCustomScheme.html"
step 2 : goto Scenario "Save As"/"Programmatic Save As" : this create a deleted file.

[ParadoxZero]

@jls28, thanks for the repro steps - let me get back to the thread once I understand it more.