Fix crash with empty conf.colors.webpage.bg on QtWebKit

(cherry picked from commit 7eee69845348e7f39930ac3a2fa4330136334566)
(cherry picked from commit a33770d50e1dad2f5b453a69cb00a2f5190ee8a7)

4 files changed, 39 insertions, 2 deletions

diff --git a/doc/changelog.asciidoc b/doc/changelog.asciidoc
index fcf3d4718..01d80fd83 100644
--- a/doc/changelog.asciidoc
+++ b/doc/changelog.asciidoc
@@ -38,6 +38,8 @@ Fixed
 - Errors while reading the state file are now displayed instead of causing a
   crash.
 - Crash when using `:debug-log-level` without a console attached.
+- Downloads are now hidden properly when the browser is in fullscreen mode.
+- Crash when setting `colors.webpage.bg` to an empty value with QtWebKit.
 
 v1.8.1 (2019-09-27)
 -------------------
diff --git a/qutebrowser/browser/webkit/webview.py b/qutebrowser/browser/webkit/webview.py
index 54258f1a8..086a43aca 100644
--- a/qutebrowser/browser/webkit/webview.py
+++ b/qutebrowser/browser/webkit/webview.py
@@ -51,7 +51,9 @@ class WebView(QWebView):
 
     STYLESHEET = """
         WebView {
+            {% if conf.colors.webpage.bg %}
             background-color: {{ qcolor_to_qsscolor(conf.colors.webpage.bg) }};
+            {% endif %}
         }
     """
 
diff --git a/tests/unit/browser/webkit/test_webview.py b/tests/unit/browser/webkit/test_webview.py
new file mode 100644
index 000000000..3b0b9d98f
--- /dev/null
+++ b/tests/unit/browser/webkit/test_webview.py
@@ -0,0 +1,32 @@
+# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
+
+# Copyright 2019 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+#
+# This file is part of qutebrowser.
+#
+# qutebrowser is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# qutebrowser is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.
+
+import pytest
+webview = pytest.importorskip('qutebrowser.browser.webkit.webview')
+
+
+@pytest.fixture
+def real_webview(webkit_tab, qtbot):
+    wv = webview.WebView(win_id=0, tab_id=0, tab=webkit_tab, private=False)
+    qtbot.add_widget(wv)
+    return wv
+
+
+def test_background_color_none(config_stub, real_webview):
+    config_stub.val.colors.webpage.bg = None
diff --git a/tox.ini b/tox.ini
index 344ccde97..f47952e36 100644
--- a/tox.ini
+++ b/tox.ini
@@ -193,14 +193,15 @@ commands = eslint --color --report-unused-disable-directives .
 
 [testenv:mypy]
 basepython = {env:PYTHON:python3}
-passenv =
+passenv = TERM
 deps =
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/misc/requirements/requirements-dev.txt
+    -r{toxinidir}/misc/requirements/requirements-tests.txt
     -r{toxinidir}/misc/requirements/requirements-pyqt.txt
     -r{toxinidir}/misc/requirements/requirements-mypy.txt
 commands =
-    {envpython} -m mypy qutebrowser {posargs}
+    {envpython} -m mypy qutebrowser tests {posargs}
 
 [testenv:sphinx]
 basepython = {env:PYTHON:python3}