Revert zero counts

This initially seemed like a nice feature, but it means 0 can't be bound
as a separate key anymore, and 0<Esc> gives weird error messages...

Reverts #1953.
Fixes #2032.

doc/help/commands.asciidoc

@@ -837,8 +837,7 @@ If neither count nor index are given, it behaves like tab-next. If both are give
 
 
 ==== count
-The tab index to focus, starting with 1. The special value 0 focuses the rightmost tab.
+The tab index to focus, starting with 1.
-
 
 [[tab-move]]
 === tab-move

qutebrowser/browser/commands.py

@@ -959,7 +959,7 @@ class CommandDispatcher:
 
     @cmdutils.register(instance='command-dispatcher', scope='window')
     @cmdutils.argument('index', choices=['last'])
-    @cmdutils.argument('count', count=True, zero_count=True)
+    @cmdutils.argument('count', count=True)
     def tab_focus(self, index: typing.Union[str, int]=None, count=None):
         """Select the tab given as argument/[count].
 
@@ -972,7 +972,6 @@ class CommandDispatcher:
                    Negative indices count from the end, such that -1 is the
                    last tab.
             count: The tab index to focus, starting with 1.
-                   The special value 0 focuses the rightmost tab.
         """
         if index == 'last':
             self._tab_focus_last()
@@ -982,9 +981,8 @@ class CommandDispatcher:
         if index is None:
             self.tab_next()
             return
-        elif index == 0:
+
-            index = self._count()
+        if index < 0:
-        elif index < 0:
             index = self._count() + index + 1
 
         if 1 <= index <= self._count():

qutebrowser/commands/command.py

@@ -34,14 +34,11 @@ class ArgInfo:
     """Information about an argument."""
 
     def __init__(self, win_id=False, count=False, hide=False, metavar=None,
-                 zero_count=False, flag=None, completion=None, choices=None):
+                 flag=None, completion=None, choices=None):
         if win_id and count:
             raise TypeError("Argument marked as both count/win_id!")
-        if zero_count and not count:
-            raise TypeError("zero_count argument cannot exist without count!")
         self.win_id = win_id
         self.count = count
-        self.zero_count = zero_count
         self.flag = flag
         self.hide = hide
         self.metavar = metavar
@@ -51,7 +48,6 @@ class ArgInfo:
     def __eq__(self, other):
         return (self.win_id == other.win_id and
                 self.count == other.count and
-                self.zero_count == other.zero_count and
                 self.flag == other.flag and
                 self.hide == other.hide and
                 self.metavar == other.metavar and
@@ -61,7 +57,6 @@ class ArgInfo:
     def __repr__(self):
         return utils.get_repr(self, win_id=self.win_id, count=self.count,
                               flag=self.flag, hide=self.hide,
-                              zero_count=self.zero_count,
                               metavar=self.metavar, completion=self.completion,
                               choices=self.choices, constructor=True)
 
@@ -142,7 +137,6 @@ class Command:
         self.opt_args = collections.OrderedDict()
         self.namespace = None
         self._count = None
-        self._zero_count = None
         self.pos_args = []
         self.desc = None
         self.flags_with_args = []
@@ -154,7 +148,7 @@ class Command:
 
         self._inspect_func()
 
-    def _check_prerequisites(self, win_id, count):
+    def _check_prerequisites(self, win_id):
         """Check if the command is permitted to run currently.
 
         Args:
@@ -170,11 +164,6 @@ class Command:
                 "{}: Only available with {} "
                 "backend.".format(self.name, self.backend.name))
 
-        if count == 0 and not self._zero_count:
-            raise cmdexc.PrerequisitesError(
-                "{}: A zero count is not allowed for this command!"
-                .format(self.name))
-
         if self.deprecated:
             message.warning('{} is deprecated - {}'.format(self.name,
                                                            self.deprecated))
@@ -246,9 +235,6 @@ class Command:
                 assert param.kind != inspect.Parameter.POSITIONAL_ONLY
                 if param.name == 'self':
                     continue
-                arg_info = self.get_arg_info(param)
-                if arg_info.count:
-                    self._zero_count = arg_info.zero_count
                 if self._inspect_special_param(param):
                     continue
                 if (param.kind == inspect.Parameter.KEYWORD_ONLY and
@@ -532,7 +518,7 @@ class Command:
                 e.status, e))
             return
         self._count = count
-        self._check_prerequisites(win_id, count)
+        self._check_prerequisites(win_id)
         posargs, kwargs = self._get_call_args(win_id)
         log.commands.debug('Calling {}'.format(
             debug_utils.format_call(self.handler, posargs, kwargs)))

qutebrowser/keyinput/basekeyparser.py

@@ -147,6 +147,9 @@ class BaseKeyParser(QObject):
             (countstr, cmd_input) = re.match(r'^(\d*)(.*)',
                                              self._keystring).groups()
             count = int(countstr) if countstr else None
+            if count == 0 and not cmd_input:
+                cmd_input = self._keystring
+                count = None
         else:
             cmd_input = self._keystring
             count = None

tests/end2end/features/misc.feature

@@ -529,10 +529,6 @@ Feature: Various utility commands.
         And I set general -> private-browsing to false
         Then the page should contain the plaintext "Local storage status: not working"
 
-    Scenario: Using 0 as count
-        When I run :scroll down with count 0
-        Then the error "scroll: A zero count is not allowed for this command!" should be shown
-
     @no_xvfb
     Scenario: :window-only
         Given I run :tab-only

tests/end2end/features/tabs.feature

@@ -255,6 +255,7 @@ Feature: Tab management
             - data/numbers/2.txt (active)
             - data/numbers/3.txt
 
+    Scenario: :tab-focus with invalid negative index
     Scenario: :tab-focus with count 0
         When I open data/numbers/1.txt
         And I open data/numbers/2.txt in a new tab
@@ -266,7 +267,6 @@ Feature: Tab management
             - data/numbers/2.txt
             - data/numbers/3.txt (active)
 
-    Scenario: :tab-focus with invalid negative index
         When I open data/numbers/1.txt
         And I open data/numbers/2.txt in a new tab
         And I open data/numbers/3.txt in a new tab

tests/unit/commands/test_cmdutils.py

@@ -423,16 +423,6 @@ class TestArgument:
 
         assert str(excinfo.value) == "Argument marked as both count/win_id!"
 
-    def test_count_and_zero_count_arg(self):
-        with pytest.raises(TypeError) as excinfo:
-            @cmdutils.argument('arg', count=False, zero_count=True)
-            def fun(arg=0):
-                """Blah."""
-                pass
-
-        expected = "zero_count argument cannot exist without count!"
-        assert str(excinfo.value) == expected
-
     def test_no_docstring(self, caplog):
         with caplog.at_level(logging.WARNING):
             @cmdutils.register()

tests/unit/keyinput/test_basekeyparser.py

@@ -245,6 +245,12 @@ class TestKeyChain:
             'ba', keyparser.Type.chain, None)
         assert keyparser._keystring == ''
 
+    def test_0_press(self, handle_text, keyparser):
+        handle_text((Qt.Key_0, '0'))
+        keyparser.execute.assert_called_once_with(
+            '0', keyparser.Type.chain, None)
+        assert keyparser._keystring == ''
+
     def test_ambiguous_keychain(self, qapp, handle_text, config_stub,
                                 keyparser):
         config_stub.data = CONFIG
@@ -308,8 +314,9 @@ class TestCount:
 
     def test_count_0(self, handle_text, keyparser):
         handle_text((Qt.Key_0, '0'), (Qt.Key_B, 'b'), (Qt.Key_A, 'a'))
-        keyparser.execute.assert_called_once_with(
+        calls = [mock.call('0', keyparser.Type.chain, None),
-            'ba', keyparser.Type.chain, 0)
+                 mock.call('ba', keyparser.Type.chain, None)]
+        keyparser.execute.assert_has_calls(calls)
         assert keyparser._keystring == ''
 
     def test_count_42(self, handle_text, keyparser):