Make console available in PAC files

doc/changelog.asciidoc

@@ -54,6 +54,7 @@ Changed
 - Various small performance improvements for hints and the completion.
 - The Wayland check for QtWebEngine is now disabled on Qt >= 5.11.2, as those
   versions should work without any issues.
+- The JavaScript `console` object is now available in PAC files.
 
 Fixed
 ~~~~~

qutebrowser/browser/network/pac.py

@@ -180,6 +180,8 @@ class PACResolver:
         """
         self._engine = QJSEngine()
 
+        self._engine.installExtensions(QJSEngine.ConsoleExtension)
+
         self._ctx = _PACContext(self._engine)
         self._engine.globalObject().setProperty(
             "PAC", self._engine.newQObject(self._ctx))

tests/unit/browser/webkit/network/test_pac.py

@@ -205,6 +205,20 @@ def test_secret_url(url, has_secret, from_file):
     res.resolve(QNetworkProxyQuery(QUrl(url)), from_file=from_file)
 
 
+def test_logging(qtlog):
+    """Make sure console.log() works for PAC files."""
+    test_str = """
+        function FindProxyForURL(domain, host) {
+            console.log("logging test");
+            return "DIRECT";
+        }
+    """
+    res = pac.PACResolver(test_str)
+    res.resolve(QNetworkProxyQuery(QUrl("https://example.com/test")))
+    assert len(qtlog.records) == 1
+    assert qtlog.records[0].message == 'logging test'
+
+
 def fetcher_test(test_str):
     class PACHandler(http.server.BaseHTTPRequestHandler):
         def do_GET(self):