Use stateful CookieJar in Redirector

As [mentioned](..httprb/issues/264#issuecomment-157070867) in httprb#264, CookieJar
implements cookie domain scoping rules, which is useful when issuing
redirects across domains.

Resolves: httprb#264

lib/http/client.rb

@@ -40,7 +40,7 @@ def request(verb, uri, opts = {}) # rubocop:disable Style/OptionHash
     def build_request(verb, uri, opts = {}) # rubocop:disable Style/OptionHash
       opts    = @default_options.merge(opts)
       uri     = make_request_uri(uri, opts)
-      headers = make_request_headers(opts)
+      headers = make_request_headers(uri, opts)
       body    = make_request_body(opts, headers)
 
       req = HTTP::Request.new(
@@ -147,19 +147,27 @@ def make_request_uri(uri, opts)
     end
 
     # Creates request headers with cookies (if any) merged in
-    def make_request_headers(opts)
+    def make_request_headers(uri, opts)
       headers = opts.headers
 
       # Tell the server to keep the conn open
       headers[Headers::CONNECTION] = default_options.persistent? ? Connection::KEEP_ALIVE : Connection::CLOSE
 
-      cookies = opts.cookies.values
+      followjar = opts.follow && opts.follow[:jar]
 
-      unless cookies.empty?
-        cookies = opts.headers.get(Headers::COOKIE).concat(cookies).join("; ")
-        headers[Headers::COOKIE] = cookies
+      hash_cookies = opts.cookies.values
+      header_cookies = opts.headers.get(Headers::COOKIE)
+      followjar_cookies = followjar ? followjar.each(uri).map(&:cookie_value) : []
+
+      sync_to_followjar = followjar ? hash_cookies + header_cookies.join.split("; ") : []
+      sync_to_followjar.each do |name_val|
+        name, value = name_val.split("=", 2)
+        followjar << Cookie.new(name, value, :domain => uri, :secure => uri.https?, :path => "/")
       end
 
+      cookies = header_cookies + hash_cookies + followjar_cookies
+      headers[Headers::COOKIE] = cookies.join("; ") unless cookies.empty?
+
       headers
     end
 

lib/http/redirector.rb

@@ -39,9 +39,11 @@ class EndlessRedirectError < TooManyRedirectsError; end
     # @param [Hash] opts
     # @option opts [Boolean] :strict (true) redirector hops policy
     # @option opts [#to_i] :max_hops (5) maximum allowed amount of hops
+    # @option opts [HTTP::CookieJar] :jar (HTTP::CookieJar.new) stateful CookieJar used across hops
     def initialize(opts = {}) # rubocop:disable Style/OptionHash
       @strict   = opts.fetch(:strict, true)
       @max_hops = opts.fetch(:max_hops, 5).to_i
+      @jar      = opts.fetch(:jar, CookieJar.new)
     end
 
     # Follows redirects until non-redirect response found
@@ -61,6 +63,7 @@ def perform(request, response)
         # XXX(ixti): using `Array#inject` to return `nil` if no Location header.
         @request  = redirect_to(@response.headers.get(Headers::LOCATION).inject(:+))
         @response = yield @request
+        @response.cookies.inject(@jar, :<<)
       end
 
       @response
@@ -77,7 +80,8 @@ def too_many_hops?
     # Check if we got into an endless loop
     # @return [Boolean]
     def endless_loop?
-      2 <= @visited.count(@visited.last)
+      visits = @visited.count(@visited.last)
+      @visited.last == @visited.first ? visits > 2 : visits > 1 # allow retrying first uri once
     end
 
     # Redirect policy for follow
@@ -94,8 +98,10 @@ def redirect_to(uri)
       end
 
       verb = :get if !SEE_OTHER_ALLOWED_VERBS.include?(verb) && 303 == code
+      redirect_uri = @request.uri.join(uri)
+      cookies_raw = @jar.each(redirect_uri).map(&:cookie_value).join("; ")
 
-      @request.redirect(uri, verb)
+      @request.redirect(uri, verb, :cookies_raw => cookies_raw)
     end
   end
 end

lib/http/request.rb

@@ -97,9 +97,10 @@ def initialize(opts)
     end
 
     # Returns new Request with updated uri
-    def redirect(uri, verb = @verb)
+    def redirect(uri, verb = @verb, cookies_raw: nil)
       headers = self.headers.dup
       headers.delete(Headers::HOST)
+      headers[Headers::COOKIE] = cookies_raw if cookies_raw
 
       self.class.new(
         :verb           => verb,