Customizer extension fails on some server (in core)

[afzaalpersonal]

The following line in the extension customizer results in a 404 error on some sites:

$this->_extension_url = site_url( str_replace( trailingslashit( str_replace( '\\', '/', ABSPATH ) ), '', $this->_extension_dir ) );

Would it be a problem to change this to:

$this->_extension_url = site_url( str_replace( trailingslashit( str_replace( '\\', '/', ABSPATH ) ), '/', $this->_extension_dir ) );

This seems to fix the 404 issue. Thanks in advance!

[kprovance]

I guess we'll find out. Addressed in v.3.5.7.11