lib/instana/instrumentation/rack.rb in instana-1.8.2 vs lib/instana/instrumentation/rack.rb in instana-1.8.3

@@ -1,6 +1,6 @@
-# FIXME: We really only need "cgi/util" here but Ruby 2.4.1 has an issue:
+# Note: We really only need "cgi/util" here but Ruby 2.4.1 has an issue:
 # https://bugs.ruby-lang.org/issues/13539
 require "cgi"
 
 module Instana
   class Rack
@@ -18,10 +18,10 @@
       elsif env.key?('SERVER_NAME')
         kvs[:http][:host] = env['SERVER_NAME']
       end
 
       if ::Instana.agent.extra_headers
-        for custom_header in agent.extra_headers
+        for custom_header in ::Instana.agent.extra_headers
           # Headers are available in this format: HTTP_X_CAPTURE_THIS
           rack_header = ('HTTP_' + custom_header.upcase).gsub('-', '_')
           if env.key?(rack_header)
             kvs["http.#{custom_header}"] = env[rack_header]
           end