Enable/Disable MDListItem raise an exception

[ikus060]

Description of the Bug

When trying to disable an MDListItem, an exception is raised.

Code and Logs

from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivymd.app import MDApp

KV = '''
<MyView>:

    MDBoxLayout:
        orientation: 'vertical'

        Button:
            text: "Toggle"
            on_release: root.toggle()

        MDListItem:
            id: item

            MDListItemHeadlineText:
                text: "Headline"

            MDListItemSupportingText:
                text: "Supporting text"

MDScreen:

    MDBoxLayout:
        id: content

        MyView:
'''

class MyView(BoxLayout):
    _trailing_icon = None

    def toggle(self):
        self.ids.item.disabled = not self.ids.item.disabled

class Example(MDApp):

    def build(self):
        return Builder.load_string(KV)
    
Example().run()

"""


class MainApp(App):
    def build(self):
        self.root = Builder.load_string(kv)


if __name__ == '__main__':
    MainApp().run()

The exception getting raised:

   File "/home/ikus060/Downloads/test_listitem.py", line 36, in toggle
     self.ids.item.disabled = not self.ids.item.disabled
   File "kivy/weakproxy.pyx", line 35, in kivy.weakproxy.WeakProxy.__setattr__
   File "kivy/properties.pyx", line 520, in kivy.properties.Property.__set__
   File "kivy/properties.pyx", line 1662, in kivy.properties.AliasProperty.set
   File "/home/ikus060/workspace/PDSL/minarca.git/.venv/lib/python3.10/site-packages/kivy/uix/widget.py", line 1573, in set_disabled
     self.inc_disabled()
   File "/home/ikus060/workspace/PDSL/minarca.git/.venv/lib/python3.10/site-packages/kivy/uix/widget.py", line 1581, in inc_disabled
     self.property('disabled').dispatch(self)
   File "kivy/properties.pyx", line 608, in kivy.properties.Property.dispatch
   File "kivy/properties.pyx", line 625, in kivy.properties.Property.dispatch
   File "kivy/properties.pyx", line 1672, in kivy.properties.AliasProperty._dispatch
   File "kivy/_event.pyx", line 1307, in kivy._event.EventObservers.dispatch
   File "kivy/_event.pyx", line 1189, in kivy._event.EventObservers._dispatch
   File "/home/ikus060/workspace/PDSL/minarca.git/.venv/lib/python3.10/site-packages/kivy/lang/builder.py", line 60, in custom_callback
     exec(__kvlang__.co_value, idmap)
   File "<string>", line 52, in <module>
 IndexError: list index out of range

Screenshots

N/A

Versions

• OS: Linux
• Python: 3.10.12
• Kivy: 2.3.0
• KivyMD: 2.0.1.dev0

[cdavidson-project-canary]

My temporary workaround for this issue:
myMDListItem.ids.leading_container.add_widget(MDWidget())

Explanation: This prevents the index of out of range error by ensuring the leading_container layout has at least one child. This doesn't impact the appearance of the MDListItem in any noticeable way.