angular/angular.js — pull request #10091 by jamshid (2014-11-17 09:34:19+00:00)
Title: fix($http): fix response headers with an empty value

Empty response header values are legal (http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html).
Return an empty string instead of null, which is returned when the header does not exist.

Closes #7779