Allow to not send the DNT header

qutebrowser/browser/shared.py

@@ -33,9 +33,12 @@ class CallSuper(Exception):
 def custom_headers():
     """Get the combined custom headers."""
     headers = {}
-    dnt = b'1' if config.val.content.headers.do_not_track else b'0'
-    headers[b'DNT'] = dnt
-    headers[b'X-Do-Not-Track'] = dnt
+
+    dnt_config = config.val.content.headers.do_not_track
+    if dnt_config is not None:
+        dnt = b'1' if dnt_config else b'0'
+        headers[b'DNT'] = dnt
+        headers[b'X-Do-Not-Track'] = dnt
 
     for header, value in config.val.content.headers.custom.items():
         headers[header.encode('ascii')] = value.encode('ascii')

qutebrowser/config/configdata.yml

@@ -225,13 +225,15 @@ content.headers.custom:
   desc: Set custom headers for qutebrowser HTTP requests.
 
 content.headers.do_not_track:
-  type: Bool
+  type:
+    name: Bool
+    none_ok: true
   default: true
   desc: >-
     Value to send in the `DNT` header.
 
     When this is set to true, qutebrowser asks websites to not track your
-    identity.
+    identity. If set to null, the DNT header is not sent at all.
 
 content.headers.referer:
   default: same-domain

tests/end2end/features/conftest.py

@@ -499,7 +499,11 @@ def check_header(quteproc, header, value):
     content = quteproc.get_content()
     data = json.loads(content)
     print(data)
-    assert utils.pattern_match(pattern=value, value=data['headers'][header])
+    if value == '<unset>':
+        assert header not in data['headers']
+    else:
+        actual = data['headers'][header]
+        assert utils.pattern_match(pattern=value, value=actual)
 
 
 @bdd.then(bdd.parsers.parse('the page should contain the html "{text}"'))

tests/end2end/features/misc.feature

@@ -335,6 +335,12 @@ Feature: Various utility commands.
         Then the header Dnt should be set to 0
         And the header X-Do-Not-Track should be set to 0
 
+    Scenario: DNT header (unset)
+        When I set content.headers.do_not_track to <empty>
+        And I open headers
+        Then the header Dnt should be set to <unset>
+        And the header X-Do-Not-Track should be set to <unset>
+
     Scenario: Accept-Language header
         When I set content.headers.accept_language to en,de
         And I open headers