Fixed #2236 by adding instance_method_already_implemented? check for invalid attribute names (fixes #2236)

app/models/object_manager/attribute.rb

@@ -898,6 +898,13 @@ is certain attribute used by triggers, overviews or schedulers
     reserved_words = %w[destroy true false integer select drop create alter index table varchar blob date datetime timestamp]
     raise "#{name} is a reserved word, please choose a different one" if name.match?(/^(#{reserved_words.join('|')})$/)
 
+    # fixes issue #2236 - Naming an attribute "attribute" causes ActiveRecord failure
+    begin
+      ObjectLookup.by_id(object_lookup_id).constantize.instance_method_already_implemented? name
+    rescue  ActiveRecord::DangerousAttributeError => e
+      raise "#{name} is a reserved word, please choose a different one"
+    end
+
     record = object_lookup.name.constantize.new
     return true if !record.respond_to?(name.to_sym)
     raise "#{name} already exists!" if record.attributes.key?(name) && new_record?

spec/models/object_manager/attribute_spec.rb

@@ -49,4 +49,51 @@ RSpec.describe ObjectManager::Attribute, type: :model do
       end
     end
   end
+
+  describe 'check name' do
+    it 'rejects ActiveRecord reserved word "attribute"' do
+      expect do
+        ObjectManager::Attribute.add attributes_for :object_manager_attribute_text, name: 'attribute'
+      end.to raise_error 'attribute is a reserved word, please choose a different one'
+    end
+
+    it 'rejects Zammad reserved word "table"' do
+      expect do
+        ObjectManager::Attribute.add attributes_for :object_manager_attribute_text, name: 'table'
+      end.to raise_error 'table is a reserved word, please choose a different one'
+    end
+
+    it 'rejects duplicate attribute name of conflicting types' do
+      attribute = attributes_for :object_manager_attribute_text
+      ObjectManager::Attribute.add attribute
+      attribute[:data_type] = 'boolean'
+      expect do
+        ObjectManager::Attribute.add attribute
+      end.to raise_error ActiveRecord::RecordInvalid
+    end
+
+    it 'accepts duplicate attribute name on the same types (editing an existing attribute)' do
+      attribute = attributes_for :object_manager_attribute_text
+      ObjectManager::Attribute.add attribute
+      expect do
+        ObjectManager::Attribute.add attribute
+      end.to_not raise_error
+    end
+
+    it 'accepts duplicate attribute name on compatible types (editing the type of an existing attribute)' do
+      attribute = attributes_for :object_manager_attribute_text
+      ObjectManager::Attribute.add attribute
+      attribute[:data_type] = 'select'
+      attribute[:data_option_new] = { default: '', options: { 'a' => 'a' } }
+      expect do
+        ObjectManager::Attribute.add attribute
+      end.to_not raise_error
+    end
+
+    it 'accepts valid attribute names' do
+      expect do
+        ObjectManager::Attribute.add attributes_for :object_manager_attribute_text
+      end.to_not raise_error
+    end
+  end
 end