quteprocess: Add --qute-delay-start

Allows for some rudimentary debugging of subprocesses.

tests/conftest.py

@@ -219,7 +219,9 @@ def qapp(qapp):
 
 def pytest_addoption(parser):
     parser.addoption('--qute-delay', action='store', default=0, type=int,
-                     help="Delay between qutebrowser commands.")
+                     help="Delay (in ms) between qutebrowser commands.")
+    parser.addoption('--qute-delay-start', action='store', default=0, type=int,
+                     help="Delay (in ms) after qutebrowser process started.")
     parser.addoption('--qute-profile-subprocs', action='store_true',
                      default=False, help="Run cProfile for subprocesses.")
     parser.addoption('--qute-backend', action='store',

tests/end2end/fixtures/quteprocess.py

@@ -457,6 +457,21 @@ class QuteProc(testprocess.Process):
         self.wait_for(category='ipc', module='ipc', function='on_ready_read',
                       message='Read from socket *')
 
+    @contextlib.contextmanager
+    def disable_capturing(self):
+        capmanager = self.request.config.pluginmanager.getplugin("capturemanager")
+        with capmanager.global_and_fixture_disabled():
+            yield
+
+    def _after_start(self):
+        """Wait before continuing if requested, e.g. for debugger attachment."""
+        delay = self.request.config.getoption('--qute-delay-start')
+        if delay:
+            with self.disable_capturing():
+                print(f"- waiting {delay}ms for quteprocess "
+                      f"(PID: {self.proc.processId()})...")
+            time.sleep(delay / 1000)
+
     def send_ipc(self, commands, target_arg=''):
         """Send a raw command to the running IPC socket."""
         delay = self.request.config.getoption('--qute-delay')