This is the current branch that you should add all patches to.

Please read the patching plugin documentation: https://github.com/creativestyle/composer-plugin-patchset/

Especially the usage section: https://github.com/creativestyle/composer-plugin-patchset/blob/master/docs/usage.md

For up-to-date documentation check out the wiki: https://jira.pluswerk.ag/wiki/display/CSHOP/Patching magento and other composer packages