fix(nested): don't toggle disabled children

[johnleider]

fixes #20386

Description

Markup:

<template>
  <pre>{{ JSON.stringify(model, null, 2) }}</pre>
  <v-treeview
    v-model="model"
    :items="items"
    select-strategy="classic"
    item-props
    open-all
    selectable
  />
</template>

<script>
  export default {
    data: () => ({
      model: [],
      items: [
        {
          value: 1,
          id: 1,
          title: 'Applications :',
          disabled: false,
          children: [
            {
              value: 2,
              id: 2,
              title: 'Calendar : app',
              disabled: false,
              children: [
                { value: 12, id: 12, title: 'Calendar : app2', disabled: false },
                { value: 13, id: 13, title: 'Chrome : app2', disabled: true },
                { value: 14, id: 14, title: 'Webstorm : app2', disabled: false },
              ],
            },
            { value: 3, id: 3, title: 'Chrome : app', disabled: false },
            { value: 4, id: 4, title: 'Webstorm : app', disabled: false },
          ],
        },
      ],
    }),
  }
</script>

[KaelWD]

Wondering if this should be indeterminate instead, not all the children are actually selected.

3.8 adds select-strategy="trunk" which is classic with a different out function, does that need to account for this too?

[yuwu9145]

return-object is usually vulnerable when nested composable has changes, so probably better add a test case to cover return-object as well

[johnleider]

Wondering if this should be indeterminate instead, not all the children are actually selected.

I fiddled with this and was ultimately unsuccessful in getting the clicked on element that has the disabled children to default to the indeterminate state.