[Problem/Bug]: WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS wins over an explicit AdditionalBrowserArguments property

[harunurhan]

What happened?

I expect that when you specify AdditionalBrowserArguments when creating the webview2 argument, it would overwrite the global env variable WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS, however that is NOT the case.

Importance

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

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

No response

SDK Version

No response

Framework

Winforms

Operating System

Windows 11

OS Version

No response

Repro steps

1. Set WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS env variable
2. Set AdditionalBrowserArguments property with different arguments
3. Validate which one is used

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Don't know

Last working version (if regression)

No response

[castorix]

I did some tests on Windows 10 22H2 with CreateCoreWebView2EnvironmentWithOptions + CoreWebView2EnvironmentOptions and i get same result.
EmbeddedBrowserWebView.dll calls CommandLineToArgvW with options I filled
then
EmbeddedBrowserWebView.dll calls CommandLineToArgvW with values from WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS, overwriting the first one.

I tested with
Environment.SetEnvironmentVariable("WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS", "--lang=es-ES");
then " --lang=de-DE";
for AdditionalBrowserArguments
and I get "--lang=es-ES" at end...
(default language is french)