parse_cookie(): Does not ignore empty cookies

[srittau]

parse_cookie("foo=bar; ; abc=def")
{'foo': 'bar', '; abc': 'def'}

As you can see, instead of a cookie named abc, there is one named ; abc. I came across this problem when I accidentally added an empty cookie in Chrome by calling document.cookie = "" from Javascript. Chrome then sent a Cookie header similar to the one above, which caused another cookie not to be found anymore.

[davidism]

Are you using the latest version of Werkzeug? Similar to #1118, although I'm not sure if completely empty keys were addressed. If they weren't a similar fix should be pretty straightforward, if you can submit one.

[yanigisawa]

#1301 submitted to address the empty segment issue. Travis CI build failed presumably from a timing issue.