[Problem/Bug]: Regression in file download from a new window

[deanmalone]

What happened?

When a user downloads a potentially harmful file from a new window (a download link with target=_blank), normally a warning message is displayed, like below:

However from version 133.0.3056.0 onwards this warning message is no longer shown and the file is directly downloaded without the download dialog shown.

Note: This seems to be a regression for all file downloads that open in a new window (target=_blank). The download dialog no longer appears and the file just downloads.

Importance

Important. My app's user experience is significantly compromised.

Runtime Channel

Prerelease (Edge Canary/Dev/Beta)

Runtime Version

134.0.3101.0

SDK Version

1.0.2792.45

Framework

WPF

Operating System

Windows 11, Windows 10

OS Version

No response

Repro steps

1. Build the WebView2WpfBrowser solution from the repo https://github.com/MicrosoftEdge/WebView2Samples
2. Set environment variable WEBVIEW2_RELEASE_CHANNELS to a value of 3 so that Canary runtime is selected.
3. Start the sample browser
4. Browse to https://gkerenyi.github.io/DownloadLinks
5. This page shows two links. One of them downloads an msixbundle file in the current window, the other one downloads the same file in a new window (using target=_blank).
6. Click the first link and observe that harmful file warning message is displayed as expected.
7. Click the second link and notice that there is no warning message shown and the file is downloaded.

Expected
The harmful file warning message is displayed in both cases.
When downloading a normal file the download dialog should appear.

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Regression in newer Runtime

Last working version (if regression)

133.0.3056.0