page: fix page mode when loading about:blank

Author: krichprollsch

src/browser/page.zig

@@ -549,11 +549,16 @@ pub const Page = struct {
             .body = opts.body != null,
         });
 
-        // if the url is about:blank, nothing to do.
+        // if the url is about:blank, we load an empty HTML document in the
+        // page and dispatch the events.
         if (std.mem.eql(u8, "about:blank", request_url)) {
             const html_doc = try parser.documentHTMLParseFromStr("");
             try self.setDocument(html_doc);
 
+            // Assume we parsed the document.
+            // It's important to force a reset during the following navigation.
+            self.mode = .parsed;
+
             // We do not processHTMLDoc here as we know we don't have any scripts
             // This assumption may be false when CDP Page.addScriptToEvaluateOnNewDocument is implemented
             self.documentIsComplete();