From 39c7e8e51f9d0e12c9f450333e79b4bb0facdb5a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oliver=20G=C3=BCnther?= <mail@oliverguenther.de>
Date: Wed, 11 Jan 2023 08:55:15 +0100
Subject: [PATCH] Don't use implicitly build custom_values for change detection

---
 app/models/custom_value.rb                            |  4 ++++
 .../acts_as_customizable/lib/acts_as_customizable.rb  |  3 +++
 .../work_package_acts_as_customizable_spec.rb         | 11 +++++++++++
 3 files changed, 18 insertions(+)

diff --git a/app/models/custom_value.rb b/app/models/custom_value.rb
index 4a754132fc..47571448c2 100644
--- a/app/models/custom_value.rb
+++ b/app/models/custom_value.rb
@@ -61,6 +61,10 @@ class CustomValue < ApplicationRecord
     end
   end
 
+  def default?
+    value == custom_field.default_value
+  end
+
   protected
 
   def validate_presence_of_required_value
diff --git a/lib_static/plugins/acts_as_customizable/lib/acts_as_customizable.rb b/lib_static/plugins/acts_as_customizable/lib/acts_as_customizable.rb
index 722a9f2889..4d50c786e4 100644
--- a/lib_static/plugins/acts_as_customizable/lib/acts_as_customizable.rb
+++ b/lib_static/plugins/acts_as_customizable/lib/acts_as_customizable.rb
@@ -256,6 +256,9 @@ module Redmine
             # Skip when the old value equals the new value (no change happened).
             next cfv_changes if value_was == cfv.value
 
+            # Skip when the new value is the default value
+            next cfv_changes if value_was.nil? && cfv.default?
+
             cfv_changes.merge("custom_field_#{cfv.custom_field_id}": [value_was, cfv.value])
           end
         end
diff --git a/spec/models/work_package/work_package_acts_as_customizable_spec.rb b/spec/models/work_package/work_package_acts_as_customizable_spec.rb
index 6ce4144292..0bdba6a4e2 100644
--- a/spec/models/work_package/work_package_acts_as_customizable_spec.rb
+++ b/spec/models/work_package/work_package_acts_as_customizable_spec.rb
@@ -135,5 +135,16 @@ describe WorkPackage, 'acts_as_customizable' do
     before do
       setup_custom_field(custom_field)
     end
+
+    context 'with a default value' do
+      before do
+        custom_field.update! default_value: 'foobar'
+        model_instance.custom_values.destroy_all
+      end
+
+      it 'returns no changes' do
+        expect(model_instance.custom_field_changes).to be_empty
+      end
+    end
   end
 end