Patched serialized_attributes for 1.8.7

I really need to discontinue support for 1.8.7...

1 files changed, 5 insertions, 2 deletions

diff --git a/lib/axlsx/util/serialized_attributes.rb b/lib/axlsx/util/serialized_attributes.rb
index 85a7feba..59efbc9f 100644
--- a/lib/axlsx/util/serialized_attributes.rb
+++ b/lib/axlsx/util/serialized_attributes.rb
@@ -16,10 +16,13 @@ module Axlsx
     end
 
     def serialized_attributes(str = '', additional_attributes = {})
-      key_value_pairs = instance_values.select do |key, value|
-        self.class.xml_attributes.include?(key.to_sym) && value != nil
+      key_value_pairs = instance_values
+      key_value_pairs.each do |key, value|
+        key_value_pairs.delete(key) if value == nil
+        key_value_pairs.delete(key) unless self.class.xml_attributes.include?(key.to_sym)
       end
       key_value_pairs.merge! additional_attributes
+
       key_value_pairs.each do |key, value|
         str << "#{Axlsx.camel(key, false)}='#{value}' "
       end