Use ${_monospace} for default hints font

doc/help/settings.asciidoc

@@ -2194,7 +2194,7 @@ Default: +pass:[8pt ${_monospace}]+
 === hints
 Font used for the hints.
 
-Default: +pass:[bold 13px Monospace]+
+Default: +pass:[bold 13px ${_monospace}]+
 
 [[fonts-debug-console]]
 === debug-console

qutebrowser/config/config.py

@@ -322,6 +322,16 @@ def _transform_hint_color(val):
         return val
 
 
+def _transform_hint_font(val):
+    """Transformer for fonts -> hints."""
+    match = re.fullmatch(r'(.*\d+p[xt]) Monospace', val)
+    if match:
+        # Close enough to the old default:
+        return match.group(1) + ' ${_monospace}'
+    else:
+        return val
+
+
 class ConfigManager(QObject):
 
     """Configuration manager for qutebrowser.
@@ -407,6 +417,7 @@ class ConfigManager(QObject):
         ('colors', 'hints.bg'): _transform_hint_color,
         ('colors', 'hints.fg'): _transform_hint_color,
         ('colors', 'hints.fg.match'): _transform_hint_color,
+        ('fonts', 'hints'): _transform_hint_font,
     }
 
     changed = pyqtSignal(str, str)

qutebrowser/config/configdata.py

@@ -1305,7 +1305,7 @@ def data(readonly=False):
              "Font used for the downloadbar."),
 
             ('hints',
-             SettingValue(typ.Font(), 'bold 13px Monospace'),
+             SettingValue(typ.Font(), 'bold 13px ${_monospace}'),
              "Font used for the hints."),
 
             ('debug-console',

tests/unit/config/test_config.py

@@ -256,6 +256,15 @@ class TestTransformers:
     def test_hint_color(self, val, expected):
         assert config._transform_hint_color(val) == expected
 
+    @pytest.mark.parametrize('val, expected', [
+        ('bold 12pt Monospace', 'bold 12pt ${_monospace}'),
+        ('23pt Monospace', '23pt ${_monospace}'),
+        ('bold 12pt ${_monospace}', 'bold 12pt ${_monospace}'),
+        ('bold 12pt Comic Sans MS', 'bold 12pt Comic Sans MS'),
+    ])
+    def test_hint_font(self, val, expected):
+        assert config._transform_hint_font(val) == expected
+
 
 class TestKeyConfigParser: