test: Avoid scrolling race with session menu

The `<TopNav>` has a hackish `handleClickOutside()` that reacts to
any "blur" event anywhere on the menu. With the right timing (which
happens with `TestKerberos.testNegotiate` on our CI), opening the
session menu and scrolling a bit triggers a blur event, which closes the
menu again.

Avoid this by disabling the "scroll into view" part of the mouse click.
We don't need it in this case, as we just scrolled the session menu
opener itself in the previous step.

test/common/testlib.py

@@ -490,7 +490,8 @@ def mouse(
         ctrlKey: bool = False,
         shiftKey: bool = False,
         altKey: bool = False,
-        metaKey: bool = False
+        metaKey: bool = False,
+        scrollVisible: bool = True,
     ) -> None:
         """Simulate a browser mouse event
 
@@ -503,6 +504,7 @@ def mouse(
         :param shiftKey: press the shift key
         :param altKey: press the alt key
         :param metaKey: press the meta key
+        :param scrollVisible: set to False in rare cases where scrolling an element into view triggers side effects
         """
         self.wait_visible(selector)
 
@@ -515,7 +517,7 @@ def mouse(
 
         # For Firefox and regular clicks, use the BiDi API, which is more realistic -- it doesn't
         # sidestep the browser
-        element = self.call_js_func('ph_find_scroll_into_view', selector)
+        element = self.call_js_func('ph_find_scroll_into_view' if scrollVisible else 'ph_find', selector)
 
         # btn=2 for context menus doesn't work with ph_mouse(); so translate the old ph_mouse() API
         if event == "contextmenu":
@@ -1021,7 +1023,9 @@ def logout(self) -> None:
             # happens when cockpit is still running
             self.open_session_menu()
             try:
-                self.click('#logout')
+                # HACK: scrolling into view sometimes triggers TopNav's handleClickOutside() hack
+                # we don't need it here, if the session menu is visible then so is the dropdown
+                self.mouse('#logout', "click", scrollVisible=False)
             except RuntimeError as e:
                 # logging out does destroy the current frame context, it races with the CDP driver finishing the command
                 if "Execution context was destroyed" not in str(e):