onerror memory leak

[dgeibi]

• Operating System: Mac
• Node Version: 12
• NPM Version: 12.18.2
• webpack Version: 4.44.2
• mini-css-extract-plugin Version: 1.2.0
• browser: chrome 86.0.4240.111

Expected Behavior

should unref onerror after onload

Actual Behavior

onerror remains in the memory

Code

https://github.com/dgeibi/mini-css-extract-plugin-mem-leak-demo

How Do We Reproduce?

git clone https://github.com/dgeibi/mini-css-extract-plugin-mem-leak-demo
cd mini-css-extract-plugin-mem-leak-demo
npm i
npm run build
# open dist/index.html with chrome

[alexander-akait]

PR welcome, easy to fix

[alexander-akait]

Big thanks!