Problem when a v-model end with spaces

[Leocardoso94]

Version

2.5.13

Reproduction link

https://codepen.io/leocardoso/pen/OQqNYz?editors=1011

Steps to reproduce

Create an input with a v-model like

And try to change its value

What is expected?

The value of model change

What is actually happening?

The value of model doesn't change and it creates a new property to the Object ended with space like obj['value ']

[yyx990803]

fixed via #7735 / #7737