Manual fixups for ImportErrors lost in rewrite

Fixups for commit PyQt import rewrite commit "Re-write PyQt5 imports to be via our wrapper."

Import not at the top of the file where mostly moved up there. Where
they were inside a try/except block they were replaced with `pass`
(why!). With the current setup of having everything imported into qt.py
we don't get import errors anymore anyway. So affected places have been
changed to check for None.

This has not currently been well tested. We might have to move some of
the conditional checks into qt.py.

I identified these pieces of code by looking for `^+ * pass$` in the
diff.

11 files changed, 26 insertions, 58 deletions

diff --git a/qutebrowser/browser/webengine/webenginetab.py b/qutebrowser/browser/webengine/webenginetab.py
index a0a83d7a7..38d8b5e7b 100644
--- a/qutebrowser/browser/webengine/webenginetab.py
+++ b/qutebrowser/browser/webengine/webenginetab.py
@@ -119,9 +119,7 @@ class _WebEngineSearchWrapHandler:
         if not qtutils.version_check("5.14"):
             return
 
-        try:
-            pass
-        except ImportError:
+        if not hasattr(QtWebEngineCore, 'QWebEngineFindTextResult'):
             # WORKAROUND for some odd PyQt/packaging bug where the
             # findTextResult signal is available, but QWebEngineFindTextResult
             # is not. Seems to happen on e.g. Gentoo.
@@ -1692,11 +1690,7 @@ class WebEngineTab(browsertab.AbstractTab):
         page.navigation_request.connect(self._on_navigation_request)
         page.printRequested.connect(self._on_print_requested)
 
-        try:
-            pass
-        except ImportError:
-            pass
-        else:
+        if QtWebEngineWidgets.QWebEngineClientCertificateSelection:
             page.selectClientCertificate.connect(
                 self._on_select_client_certificate)
 
diff --git a/qutebrowser/misc/backendproblem.py b/qutebrowser/misc/backendproblem.py
index 7cd292294..c318c2f80 100644
--- a/qutebrowser/misc/backendproblem.py
+++ b/qutebrowser/misc/backendproblem.py
@@ -263,21 +263,16 @@ class _BackendProblemChecker:
 
     def _try_import_backends(self) -> _BackendImports:
         """Check whether backends can be imported and return BackendImports."""
-        # pylint: disable=unused-import
         results = _BackendImports()
 
-        try:
-            pass
-        except (ImportError, ValueError) as e:
-            results.webkit_error = str(e)
-        else:
+        if QtWebKit and QtWebKitWidgets and QtWebKit.qWebKitVersion:
             if not qtutils.is_new_qtwebkit():
                 results.webkit_error = "Unsupported legacy QtWebKit found"
+        else:
+            results.webkit_error = "Some required QtWebKit modules not found"
 
-        try:
-            pass
-        except (ImportError, ValueError) as e:
-            results.webengine_error = str(e)
+        if not QtWebEngineWidgets:
+            results.webengine_error = "QtWebEngineWidgets not available"
 
         return results
 
diff --git a/qutebrowser/misc/earlyinit.py b/qutebrowser/misc/earlyinit.py
index fe174991f..2c71804e7 100644
--- a/qutebrowser/misc/earlyinit.py
+++ b/qutebrowser/misc/earlyinit.py
@@ -78,7 +78,7 @@ def _die(message, exception=None):
         message: The message to display.
         exception: The exception object if we're handling an exception.
     """
-    from qutebrowser.qt import QtWidgets, QtWebEngineWidgets, QtNetwork, QtCore
+    from qutebrowser.qt import QtWidgets, QtCore
     if (('--debug' in sys.argv or '--no-err-windows' in sys.argv) and
             exception is not None):
         print(file=sys.stderr)
@@ -160,6 +160,7 @@ def check_pyqt():
 
 def qt_version(qversion=None, qt_version_str=None):
     """Get a Qt version string based on the runtime/compiled versions."""
+    from qutebrowser.qt import QtCore
     if qversion is None:
         qversion = QtCore.qVersion()
     if qt_version_str is None:
@@ -173,6 +174,7 @@ def qt_version(qversion=None, qt_version_str=None):
 
 def check_qt_version():
     """Check if the Qt version is recent enough."""
+    from qutebrowser.qt import QtCore
     try:
         qt_ver = QtCore.QLibraryInfo.version().normalized()
         recent_qt_runtime = qt_ver >= QtCore.QVersionNumber(5, 12)  # type: ignore[operator]
@@ -194,9 +196,8 @@ def check_qt_version():
 
 def check_ssl_support():
     """Check if SSL support is available."""
-    try:
-        pass
-    except ImportError:
+    from qutebrowser.qt import QtNetwork
+    if not QtNetwork or not QtNetwork.QSslSocket:
         _die("Fatal error: Your Qt is built without SSL support.")
 
 
@@ -288,7 +289,7 @@ def webengine_early_import():
     error messages in backendproblem.py are accurate.
     """
     try:
-        pass
+        from qutebrowser.qt import QtWebEngineWidgets  # pylint: disable=unused-import
     except ImportError:
         pass
 
diff --git a/qutebrowser/utils/qtutils.py b/qutebrowser/utils/qtutils.py
index 8c0f8a6be..bf109095e 100644
--- a/qutebrowser/utils/qtutils.py
+++ b/qutebrowser/utils/qtutils.py
@@ -33,10 +33,8 @@ import operator
 import contextlib
 from typing import (Any, AnyStr, TYPE_CHECKING, BinaryIO, IO, Iterator,
                     Optional, Union, Tuple, cast)
-from qutebrowser.qt import QtWebKit, QtWebEngineWidgets, QtGui
-try:
-    pass
-except ImportError:  # pragma: no cover
+from qutebrowser.qt import QtWebKit, QtGui
+if not QtWebKit:
     qWebKitVersion = None  # type: ignore[assignment]  # noqa: N816
 if TYPE_CHECKING:
     from qutebrowser.qt import QWebHistory
diff --git a/qutebrowser/utils/version.py b/qutebrowser/utils/version.py
index 6049b0708..28df9199d 100644
--- a/qutebrowser/utils/version.py
+++ b/qutebrowser/utils/version.py
@@ -38,13 +38,11 @@ from typing import (Mapping, Optional, Sequence, Tuple, ClassVar, Dict, cast,
                     TYPE_CHECKING)
 from qutebrowser.qt import QtWidgets, QtWebKit, QtWebEngine, QtNetwork
 
-try:
-    pass
-except ImportError:  # pragma: no cover
+if not QtWebKit:
     qWebKitVersion = None  # type: ignore[assignment]  # noqa: N816
-try:
-    pass
-except ImportError:  # pragma: no cover
+if QtWebEngine:
+    PYQT_WEBENGINE_VERSION_STR = QtWebEngine.PYQT_WEBENGINE_VERSION_STR
+else:
     # Added in PyQt 5.13
     PYQT_WEBENGINE_VERSION_STR = None  # type: ignore[assignment]
 
diff --git a/tests/end2end/conftest.py b/tests/end2end/conftest.py
index 6e14495e2..d8d3b7a38 100644
--- a/tests/end2end/conftest.py
+++ b/tests/end2end/conftest.py
@@ -118,12 +118,10 @@ def _get_version_tag(tag):
             reason='Needs ' + tag,
         )
     elif package == 'pyqtwebengine':
-        try:
-            pass
-        except ImportError:
-            running_version = QtCore.PYQT_VERSION
-        else:
+        if QtWebEngine:
             running_version = QtWebEngine.PYQT_WEBENGINE_VERSION
+        else:
+            running_version = QtCore.PYQT_VERSION
         return pytest.mark.skipif(
             not _check_version(
                 op_str=match.group('operator'),
diff --git a/tests/helpers/testutils.py b/tests/helpers/testutils.py
index 44a299de6..40031a433 100644
--- a/tests/helpers/testutils.py
+++ b/tests/helpers/testutils.py
@@ -272,10 +272,7 @@ def disable_seccomp_bpf_sandbox():
     This is needed for some QtWebEngine setups, with older Qt versions but
     newer kernels.
     """
-    try:
-        pass
-    except ImportError:
-        # no QtWebEngine available
+    if not QtWebEngine:
         return False
 
     affected_versions = set()
diff --git a/tests/unit/browser/test_history.py b/tests/unit/browser/test_history.py
index d757d16ba..e41998b3c 100644
--- a/tests/unit/browser/test_history.py
+++ b/tests/unit/browser/test_history.py
@@ -320,11 +320,6 @@ class TestInit:
         history.init(data_tmpdir / f'test_init_{backend}', qapp)
         assert history.web_history.parent() is qapp
 
-        try:
-            pass
-        except ImportError:
-            QWebHistoryInterface = None
-
         if backend == usertypes.Backend.QtWebKit:
             default_interface = QtWebKit.QWebHistoryInterface.defaultInterface()
             assert default_interface._history is history.web_history
diff --git a/tests/unit/completion/test_models.py b/tests/unit/completion/test_models.py
index 360ee9f8a..ceea3db35 100644
--- a/tests/unit/completion/test_models.py
+++ b/tests/unit/completion/test_models.py
@@ -31,10 +31,6 @@ from unittest import mock
 import hypothesis
 import hypothesis.strategies as hst
 import pytest
-try:
-    pass
-except ImportError:
-    pass
 
 from qutebrowser.misc import objects, guiprocess
 from qutebrowser.completion import completer
diff --git a/tests/unit/config/test_configfiles.py b/tests/unit/config/test_configfiles.py
index 460a512fa..ed7cb1714 100644
--- a/tests/unit/config/test_configfiles.py
+++ b/tests/unit/config/test_configfiles.py
@@ -166,9 +166,7 @@ def state_writer(data_tmpdir):
 
 @pytest.fixture
 def qtwe_version_patcher(monkeypatch):
-    try:
-        pass
-    except ImportError:
+    if not QtWebEngineWidgets:
         pytest.skip("QtWebEngine not available")
 
     def patch(ver):
diff --git a/tests/unit/utils/test_version.py b/tests/unit/utils/test_version.py
index d7a46ae07..d65a91082 100644
--- a/tests/unit/utils/test_version.py
+++ b/tests/unit/utils/test_version.py
@@ -1007,11 +1007,9 @@ class TestWebEngineVersions:
             if '.dev' in QtCore.PYQT_VERSION_STR:
                 pytest.skip("dev version of PyQt5")
 
-            try:
-                pass
-            except ImportError as e:
+            if not QtWebEngine or not hasattr(QtWebEngine, "PYQT_WEBENGINE_VERSION"):
                 # QtWebKit or QtWebEngine < 5.13
-                pytest.skip(str(e))
+                pytest.skip("QtWebEngine")
 
             if QtWebEngine.PYQT_WEBENGINE_VERSION >= 0x050F02:
                 # Starting with Qt 5.15.2, we can only do bad guessing anyways...