Jacek Caban (@jacek) commented about dlls/mshtml/nsio.c:
- hres = IUri_GetDisplayUri(This->uri->uri, &display_uri);
- if (FAILED(hres)) {
IBindStatusCallback_Release(&bscallback->bsc.IBindStatusCallback_iface);return NS_ERROR_UNEXPECTED;- }
- hres = IHTMLWindow2_get_name(&window->base.IHTMLWindow2_iface, &frame_name);
- if (FAILED(hres)) {
IBindStatusCallback_Release(&bscallback->bsc.IBindStatusCallback_iface);SysFreeString(display_uri);return NS_ERROR_UNEXPECTED;- }
- browser = window->base.outer_window->browser;
- hres = IDocObjectService_FireBeforeNavigate2(browser->doc->doc_object_service, NULL, display_uri, 0, frame_name, NULL, 0, NULL, TRUE, &cancel);
Doing that here would fire for each binding we perform, including things like CSS, scripts, and images. If we want to catch only document bindings, see `before_async_open` in `nsChannel_AsyncOpen`. It's currently guarded by `is_main_content_window`, so it won't trigger, and at least some of that probably should remain guarded, but I guess it would fit better there.
A test in MSHTML itself (like in `tests/htmldoc.c`) would more precisely show us how it's supposed to work, by avoiding the ieframe layer. Also, it may be more convenient to use the res: protocol and embed the source in resources, we already have a few of those. If http is important for some reason, we could add the iframe source to test.winehq.org.