fix memory leak

[Remcoman]

fixes #521

[codecov]

Codecov Report

Merging #522 into master will decrease coverage by 0.29%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master     #522     +/-   ##
=========================================
- Coverage   99.25%   98.95%   -0.3%     
=========================================
  Files          33       33             
  Lines         673      673             
  Branches      204      204             
=========================================
- Hits          668      666      -2     
- Misses          3        5      +2     
  Partials        2        2

Impacted Files	Coverage Δ
src/shared/mixin.js	94.59% <100%> (ø)	⬆️
src/utils/ensure.js	71.42% <0%> (-28.58%)	⬇️

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[pimlie]

Hey, thanks for looking into this. I have debugged this extensively in the past but unfortunately couldnt find the root cause. There indeed seems to be an issue still left but I have been unable to find a vanilla Vue.js reproduction to prove/understand whats really happening. For reference have a look at this issue: vuejs/vue#10458

If you have time, maybe you could try to create a vanilla Vue.js reproduction of this error?

Again unfortunately, using hook: events is an internal Vue.js API and I was advised at the time by the Vue core team to not use it. Because of that I will be unable to merge this PR for now, sorry.