Merge pull request #27007 from maclover7/jm-fix-26912

Don't error on an empty CONTENT_TYPE

actionpack/lib/action_dispatch/http/mime_negotiation.rb

@@ -29,8 +29,8 @@ module ActionDispatch
         content_mime_type && content_mime_type.to_s
       end
 
-      def has_content_type?
-        has_header? "CONTENT_TYPE"
+      def has_content_type? # :nodoc:
+        get_header "CONTENT_TYPE"
       end
 
       # Returns the accepted MIME type for the request.

actionpack/test/controller/params_wrapper_test.rb

@@ -212,6 +212,16 @@ class ParamsWrapperTest < ActionController::TestCase
       )
     end
   end
+
+  def test_handles_empty_content_type
+    with_default_wrapper_options do
+      @request.env["CONTENT_TYPE"] = nil
+      _controller_class.dispatch(:parse, @request, @response)
+
+      assert_equal 200, @response.status
+      assert_equal "", @response.body
+    end
+  end
 end
 
 class NamespacedParamsWrapperTest < ActionController::TestCase