[Bug Report][2.6.4] v-menu + dynamic activator, activatorFixed prop does not reset

[Kasheftin]

Environment

Vuetify Version: 2.6.4
Vue Version: 2.6.13
Browsers: Chrome 98.0.4758.102
OS: Linux x86_64

Steps to reproduce

• Click on "Dropdown" button, the menu is shown under the button;
• Click on "Toggle Menu" twice;
• Click on "Dropdown" button, the menu is shown somewhere at the left;

Expected Behavior

It should work in a stable way. Menu should be shown under "Dropdown" button

Actual Behavior

Menu shown in a different place after reinitialization

Reproduction Link

https://codepen.io/kasheftin/pen/rNpJyzm?editors=1010

[Tofandel]

Why are you attaching to a ref within itself? Do you realise the logic issue?

Your ref is actually undefined until after the vMenu has mounted

https://codepen.io/Tofandel/pen/yLprVRP?editors=1010

[Kasheftin]

Attach can be considered as a reference. This case there's no logic issue - when the menu is going to appear, it should search for an activator node and attach there. It does not matter in which order the nodes are mounted.

By reporting this issue I want to point out on the bug here,

vuetify/packages/vuetify/src/mixins/menuable/index.ts

Line 284 in 45818a5

if (this.attach !== false) return

If attach prop is dynamic, it's false initially, then activatorFixed variable can be set to true. If then activator becomes true, activatorFixed does not reset. On my opinion it should be like

if (this.attach !== false) {
  this.activatorFixed = false
  return 
}

This change solves the initial issue.

There's one more repro: https://codepen.io/kasheftin/pen/rNpJyzm
It's more artificial but it does not use attach inside activator.
Repro steps:

1. click on menu, notice it appears under the button
2. click outside to hide the menu
3. click on toggle
4. click on menu - it appears in some other place, but it does not matter
5. click outside to hide the menu
6. click on toggle to return the system to initial state
7. click on menu - now it appear in the different place