Turn off SQL history writing during end2end tests

This hopefully makes them a bit faster, and also should help with weird hangs we
had in tests.

qutebrowser/browser/history.py

@@ -132,7 +132,7 @@ class WebHistory(sql.SqlTable):
             self._do_clear()
         else:
             message.confirm_async(self._do_clear, title="Clear all browsing "
-                                "history?")
+                                  "history?")
 
     def _do_clear(self):
         self.delete_all()
@@ -177,6 +177,9 @@ class WebHistory(sql.SqlTable):
             log.misc.warning("Ignoring invalid URL being added to history")
             return
 
+        if 'no-sql-history' in objreg.get('args').debug_flags:
+            return
+
         atime = int(atime) if (atime is not None) else int(time.time())
         self.insert({'url': self._format_url(url),
                      'title': title,

qutebrowser/qutebrowser.py

@@ -150,7 +150,7 @@ def debug_flag_error(flag):
         debug-exit: Turn on debugging of late exit.
         pdb-postmortem: Drop into pdb on exceptions.
     """
-    valid_flags = ['debug-exit', 'pdb-postmortem']
+    valid_flags = ['debug-exit', 'pdb-postmortem', 'no-sql-history']
 
     if flag in valid_flags:
         return flag

tests/end2end/features/test_history_bdd.py

@@ -20,11 +20,19 @@
 import logging
 import re
 
+import pytest
 import pytest_bdd as bdd
 
 bdd.scenarios('history.feature')
 
 
+@pytest.fixture(autouse=True)
+def turn_on_sql_history(quteproc):
+    """Make sure SQL writing is enabled for tests in this module."""
+    quteproc.send_cmd(":debug-pyeval objreg.get('args').debug_flags.remove('no-sql-history')")
+    quteproc.wait_for_load_finished_url('qute://pyeval')
+
+
 @bdd.then(bdd.parsers.parse("the history should contain:\n{expected}"))
 def check_history(quteproc, httpbin, tmpdir, expected):
     path = tmpdir / 'history'

tests/end2end/fixtures/quteprocess.py

@@ -401,7 +401,8 @@ class QuteProc(testprocess.Process):
         backend = 'webengine' if self.request.config.webengine else 'webkit'
         return ['--debug', '--no-err-windows', '--temp-basedir',
                 '--json-logging', '--loglevel', 'vdebug',
-                '--backend', backend, 'about:blank']
+                '--backend', backend, '--debug-flag', 'no-sql-history',
+                'about:blank']
 
     def path_to_url(self, path, *, port=None, https=False):
         """Get a URL based on a filename for the localhost webserver.