From ad29dcce6c36855cef9c2b2ea62298b2f8fb0f26 Mon Sep 17 00:00:00 2001
From: kumojima <kumojima@gmail.com>
Date: Fri, 4 Sep 2026 20:51:19 +0900
Subject: select default_value of required custom field

---
 lib/redmine/field_format.rb                   |  8 ++++++-
 .../redmine/field_format/bool_format_test.rb  | 21 +++++++++++++++++++
 .../redmine/field_format/list_format_test.rb  | 21 +++++++++++++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/lib/redmine/field_format.rb b/lib/redmine/field_format.rb
index 46ada2817..ae18799f3 100644
--- a/lib/redmine/field_format.rb
+++ b/lib/redmine/field_format.rb
@@ -652,9 +652,15 @@ module Redmine
             blank_option = view.content_tag('option', '&nbsp;'.html_safe, :value => '')
           end
         end
+        cf = custom_value.custom_field
+        if !cf.multiple? && cf.is_required? && cf.default_value.present? && custom_value.value.blank?
+          value = cf.default_value
+        else
+          value = custom_value.value
+        end
         options_tags =
           blank_option +
-           view.options_for_select(possible_custom_value_options(custom_value), custom_value.value)
+           view.options_for_select(possible_custom_value_options(custom_value), value)
         s =
           view.select_tag(
             tag_name, options_tags,
diff --git a/test/unit/lib/redmine/field_format/bool_format_test.rb b/test/unit/lib/redmine/field_format/bool_format_test.rb
index c55d4ed1b..3860d4bd2 100644
--- a/test/unit/lib/redmine/field_format/bool_format_test.rb
+++ b/test/unit/lib/redmine/field_format/bool_format_test.rb
@@ -62,4 +62,25 @@ class Redmine::BoolFieldFormatTest < ActionView::TestCase
     tag = field.format.edit_tag(self, 'abc', 'xyz', value)
     assert_select_in tag, 'select[name=xyz]', 1
   end
+
+  def test_edit_tag_should_select_defalut_value_without_custom_value_when_required
+    field = IssueCustomField.new(:field_format => 'bool', :is_required => true, :default_value => '0')
+    value = CustomFieldValue.new(:custom_field => field, :customized => Issue.new, :value => nil)
+
+    tag = field.format.edit_tag(self, 'id', 'name', value)
+    assert_select_in tag, 'select' do
+      assert_select 'option[selected=selected]', 1
+      assert_select 'option[value=0][selected=selected]', :text => 'No'
+    end
+  end
+
+  def test_edit_tag_should_select_defalut_value_without_custom_value_when_not_required
+    field = IssueCustomField.new(:field_format => 'bool', :is_required => false, :default_value => '0')
+    value = CustomFieldValue.new(:custom_field => field, :customized => Issue.new, :value => nil)
+
+    tag = field.format.edit_tag(self, 'id', 'name', value)
+    assert_select_in tag, 'select' do
+      assert_select 'option[selected=selected]', 0
+    end
+  end
 end
diff --git a/test/unit/lib/redmine/field_format/list_format_test.rb b/test/unit/lib/redmine/field_format/list_format_test.rb
index 50e870c98..643127ac3 100644
--- a/test/unit/lib/redmine/field_format/list_format_test.rb
+++ b/test/unit/lib/redmine/field_format/list_format_test.rb
@@ -81,6 +81,27 @@ class Redmine::ListFieldFormatTest < ActionView::TestCase
     end
   end
 
+  def test_edit_tag_should_select_defalut_value_without_custom_value_when_required
+    field = IssueCustomField.new(:field_format => 'list', :possible_values => ['Foo', 'Bar'], :is_required => true, :default_value => 'Bar')
+    value = CustomFieldValue.new(:custom_field => field, :customized => Issue.new, :value => nil)
+
+    tag = field.format.edit_tag(self, 'id', 'name', value)
+    assert_select_in tag, 'select' do
+      assert_select 'option[selected=selected]', 1
+      assert_select 'option[value=Bar][selected=selected]', :text => 'Bar'
+    end
+  end
+
+  def test_edit_tag_should_select_defalut_value_without_custom_value_when_not_required
+    field = IssueCustomField.new(:field_format => 'list', :possible_values => ['Foo', 'Bar'], :is_required => false, :default_value => 'Bar')
+    value = CustomFieldValue.new(:custom_field => field, :customized => Issue.new, :value => nil)
+
+    tag = field.format.edit_tag(self, 'id', 'name', value)
+    assert_select_in tag, 'select' do
+      assert_select 'option[selected=selected]', 0
+    end
+  end
+
   def test_edit_tag_with_multiple_should_select_current_values
     field = IssueCustomField.new(:field_format => 'list', :possible_values => ['Foo', 'Bar', 'Baz'], :is_required => false,
       :multiple => true)
-- 
2.43.0