Fix around_http_request to support multiple requests.

Fibers can only be used once so we have to create a new one for each request.

lib/vcr/configuration.rb

@@ -80,9 +80,8 @@ def around_http_request(&block)
         "VCR::Configuration#around_http_request requires fibers, " +
         "which are not available on your ruby intepreter."
     else
-      hook_decaration = caller.first
-      fiber = Fiber.new(&block)
-      before_http_request { |request| fiber.resume(request.fiber_aware) }
+      fiber, hook_decaration = nil, caller.first
+      before_http_request { |request| fiber = start_new_fiber_for(request, block) }
       after_http_request  { |request| resume_fiber(fiber, hook_decaration) }
     end
 
@@ -103,6 +102,12 @@ def resume_fiber(fiber, hook_declaration)
         "Your around_http_request hook declared at #{hook_declaration}" +
         " must call #proceed on the yielded request but did not."
     end
+
+    def start_new_fiber_for(request, block)
+      Fiber.new(&block).tap do |fiber|
+        fiber.resume(request.fiber_aware)
+      end
+    end
   end
 end
 

spec/support/shared_example_groups/hook_into_http_library.rb

@@ -192,6 +192,14 @@ def self.test_playback(description, url)
             error.message.should include(hook_declaration)
           }
         end
+
+        it 'does not get a dead fiber error when multiple requests are made' do
+          VCR.configuration.around_http_request do |request|
+            VCR.use_cassette('new_cassette', &request)
+          end
+
+          3.times { make_http_request(:get, request_url) }
+        end
       end if RUBY_VERSION >= '1.9'
 
       context "when the request is ignored" do