Delay various .show() calls until after tabs are added

With Qt 6.4, QtWebEngine closes/reopens the main window to switch the
RHI rendering mode when a QWebEngineView gets added:
https://github.com/qt/qtbase/blob/v6.4.1/src/widgets/kernel/qwidget.cpp#L10706-L10709

To avoid this, we need to make sure we only call .show() *after* adding
a tab, similarly to what Qt did too:
https://code.qt.io/cgit/qt/qtwebengine.git/commit/?id=d7e0fd5304ebdb12c6f809cdbcf8193b49b9ecd2

See #7504

----

This commit handles various simple and isolated cases. Things requiring
a bit more refactoring are handled in a separate commit.

6 files changed, 18 insertions, 22 deletions

diff --git a/qutebrowser/browser/navigate.py b/qutebrowser/browser/navigate.py
index d2783e349..148f0f6e9 100644
--- a/qutebrowser/browser/navigate.py
+++ b/qutebrowser/browser/navigate.py
@@ -219,10 +219,10 @@ def prevnext(*, browsertab, win_id, baseurl, prev=False,
         if window:
             new_window = mainwindow.MainWindow(
                 private=cur_tabbed_browser.is_private)
-            new_window.show()
             tabbed_browser = objreg.get('tabbed-browser', scope='window',
                                         window=new_window.win_id)
             tabbed_browser.tabopen(url, background=False)
+            new_window.show()
         elif tab:
             cur_tabbed_browser.tabopen(url, background=background)
         else:
diff --git a/qutebrowser/browser/shared.py b/qutebrowser/browser/shared.py
index a2313a219..92ed99584 100644
--- a/qutebrowser/browser/shared.py
+++ b/qutebrowser/browser/shared.py
@@ -360,23 +360,19 @@ def get_tab(win_id, target):
         win_id: The window ID to open new tabs in
         target: A usertypes.ClickTarget
     """
-    if target == usertypes.ClickTarget.tab:
-        bg_tab = False
-    elif target == usertypes.ClickTarget.tab_bg:
-        bg_tab = True
-    elif target == usertypes.ClickTarget.window:
-        tabbed_browser = objreg.get('tabbed-browser', scope='window',
-                                    window=win_id)
+    tabbed_browser = objreg.get('tabbed-browser', scope='window', window=win_id)
+    if target == usertypes.ClickTarget.window:
         window = mainwindow.MainWindow(private=tabbed_browser.is_private)
+        tab = window.tabbed_browser.tabopen(url=None, background=False)
         window.show()
-        win_id = window.win_id
-        bg_tab = False
-    else:
-        raise ValueError("Invalid ClickTarget {}".format(target))
+        return tab
+    elif target in [usertypes.ClickTarget.tab, usertypes.ClickTarget.tab_bg]:
+        return tabbed_browser.tabopen(
+            url=None,
+            background=target == usertypes.ClickTarget.tab_bg,
+        )
 
-    tabbed_browser = objreg.get('tabbed-browser', scope='window',
-                                window=win_id)
-    return tabbed_browser.tabopen(url=None, background=bg_tab)
+    raise ValueError(f"Invalid ClickTarget {target}")
 
 
 def get_user_stylesheet(searching=False):
diff --git a/qutebrowser/browser/webelem.py b/qutebrowser/browser/webelem.py
index 91e82ae0c..672c73fdb 100644
--- a/qutebrowser/browser/webelem.py
+++ b/qutebrowser/browser/webelem.py
@@ -405,8 +405,8 @@ class AbstractWebElement(collections.abc.MutableMapping):  # type: ignore[type-a
         elif click_target == usertypes.ClickTarget.window:
             from qutebrowser.mainwindow import mainwindow
             window = mainwindow.MainWindow(private=tabbed_browser.is_private)
-            window.show()
             window.tabbed_browser.tabopen(url)
+            window.show()
         else:
             raise ValueError("Unknown ClickTarget {}".format(click_target))
 
diff --git a/qutebrowser/mainwindow/tabbedbrowser.py b/qutebrowser/mainwindow/tabbedbrowser.py
index bcd07f088..dfebe6b48 100644
--- a/qutebrowser/mainwindow/tabbedbrowser.py
+++ b/qutebrowser/mainwindow/tabbedbrowser.py
@@ -639,11 +639,10 @@ class TabbedBrowser(QWidget):
 
         if config.val.tabs.tabs_are_windows and self.widget.count() > 0:
             window = mainwindow.MainWindow(private=self.is_private)
+            tab = window.tabbed_browser.tabopen(
+                url=url, background=background, related=related)
             window.show()
-            tabbed_browser = objreg.get('tabbed-browser', scope='window',
-                                        window=window.win_id)
-            return tabbed_browser.tabopen(url=url, background=background,
-                                          related=related)
+            return tab
 
         tab = browsertab.create(win_id=self._win_id,
                                 private=self.is_private,
diff --git a/qutebrowser/mainwindow/windowundo.py b/qutebrowser/mainwindow/windowundo.py
index 0104a8187..80f47aaaa 100644
--- a/qutebrowser/mainwindow/windowundo.py
+++ b/qutebrowser/mainwindow/windowundo.py
@@ -83,9 +83,9 @@ class WindowUndoManager(QObject):
             private=False,
             geometry=entry.geometry,
         )
-        window.show()
         window.tabbed_browser.undo_stack = entry.tab_stack
         window.tabbed_browser.undo()
+        window.show()
 
 
 def init():
diff --git a/qutebrowser/misc/sessions.py b/qutebrowser/misc/sessions.py
index bfb2d4347..53f7bf3d3 100644
--- a/qutebrowser/misc/sessions.py
+++ b/qutebrowser/misc/sessions.py
@@ -467,7 +467,6 @@ class SessionManager(QObject):
         """Turn yaml data into windows."""
         window = mainwindow.MainWindow(geometry=win['geometry'],
                                        private=win.get('private', None))
-        window.show()
         tabbed_browser = objreg.get('tabbed-browser', scope='window',
                                     window=window.win_id)
         tab_to_focus = None
@@ -480,6 +479,8 @@ class SessionManager(QObject):
                 new_tab.set_pinned(True)
         if tab_to_focus is not None:
             tabbed_browser.widget.setCurrentIndex(tab_to_focus)
+
+        window.show()
         if win.get('active', False):
             QTimer.singleShot(0, tabbed_browser.widget.activateWindow)