Seems SendProcessMessage doesnt send to the correct process

[zj0363637]

HI,

I'm trying to prevent page navigation based on policies according the the suggestion in below link:

viewtopic.php?f=6&t=10394

Which suggests:
1. Cancel all requests on OnBeforeNavigation.
2. Send a message to the browser process with the relevant request information (URL, headers, etc).
3. Evaluate the information in the browser process and either:
A. Open the link in an external browser, or
B. Ignore the request, or
C. Call CefBrowser::LoadRequest to re-start the request.

The default address is "about:blank", and if navigating to "https://www.google.com", it actually creates two renderer process, and sending BeforeNavigationMessage back to browser process (from log below its in the google renderer process), however it seems when the browser process trying to send a confirmation message back to renderer process, it always goes to the "about:blank" renderer process:

[1016/143235.495:INFO:client_app_renderer.cc(104)] OnBrowserCreated id: 2 ProcessId:18272
[1016/143235.495:INFO:client_app_renderer.cc(104)] OnBrowserCreated id: 2 ProcessId:10900
[1016/143235.499:INFO:client_app_renderer.cc(120)] OnBeforeNavigation process id: 10900 URL:about:blank
[1016/143235.500:INFO:client_app_renderer.cc(120)] OnBeforeNavigation process id: 18272 URL:https://www.google.com
[1016/143235.500:INFO:client_app_renderer.cc(137)] Sending Before Navigation Message: Current Process Id: 18272 BrowserId: 2
[1016/143235.502:INFO:client_app_renderer.cc(587)] Receiving message in: 10900 for:18272

I'm using CEF Version: 3.3163.1671.g700dc25

Thanks
Jim

[magreenblatt]

Where/how are you loading google.com? Where/when are you sending the message that arrives in the about:blank renderer after the google.com load??

[zj0363637]

Where/how are you loading google.com?
I'm creating the browser using CreateBrowserSync with "about:blank" as start url, then call LoadURL to navigate to google.com.

Where/when are you sending the message that arrives in the about:blank renderer after the google.com load??
I intercept OnBeforeNavigation in the renderer process, and return false if its "about:blank" otherwise send a message to browser process (browser->SendProcessMessage(PID_BROWSER, message);) and return true, the browser process will validate the url and if allowed then send a message back (browser->SendProcessMessage(PID_RENDERER, message);)

For more information, I've turned on --process-per-site flag, and seems another renderer process is created and will never be destroyed, which causes message always being sent to wrong process, something to do with OnBeforeNavigation cancelling.

I found another post which seems very similar to the issue I'm facing. however the ticket was marked as wont fix, not sure why.
viewtopic.php?f=6&t=10573

Thanks for looking into this.

[magreenblatt]

The new process will not be created until after the navigation commits. So, OnBeforeNavigation will be called in the current renderer, then you navigate, then the new renderer is created (OnLoadStart called). At that point your process messages should go to the new renderer.

The process-per-site flag is not supported so behaviors using that flag are undefined/untested.