fix - Add to favorites not working in IE11 - polyfill needed #12007

[z0iberg]

Fix issue that has @Req. This commit was proposed by @Req, but he doesn't make this commit.
#12007 (comment)

[violoncelloCH]

consider #12007 (comment) by @Req before merging this

[juliusknorr]

I would rather vote to add a more complete ES6 polyfill or fix the occurenced of startsWith. Probably the first one would be nice, since it would make developing plain js code a bit easier in the future. IE11 seems to be the only browser that would still need those polyfills.

https://github.com/paulmillr/es6-shim might be an oppinion. We currently already have a es6-promise polyfill (which is included unminified and has about 32kb) es6-shim has a minified size of 55kb. cc @nextcloud/javascript

[juliusknorr]

As discussed I've created a pr to add es6-shim in #12317 however for backporting, i would just use the startsWith polyfill from this PR to keep the stable branches clean from the dependency change. cc @nextcloud/javascript

[juliusknorr]

This PR got replaced by #12317 Thanks for getting this started anyway @z0iberg

[MorrisJobke]

@juliushaertl Didn't we want to backport this one to stable14?

[juliusknorr]

@MorrisJobke Backport of this in #12339