Fix NoMethodError in IssuePriority#high and #low when no default or active priorities exist (#42066).

Patch by Go MAEDA (user:maeda).


git-svn-id: https://svn.redmine.org/redmine/trunk@23431 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/issue_priority.rb

@@ -60,11 +60,15 @@ class IssuePriority < Enumeration
   end
 
   def high?
-    position > self.class.default_or_middle.position
+    return false unless (baseline_position = self.class.default_or_middle&.position)
+
+    position > baseline_position
   end
 
   def low?
-    position < self.class.default_or_middle.position
+    return false unless (baseline_position = self.class.default_or_middle&.position)
+
+    position < baseline_position
   end
 
   # Updates position_name for active priorities

test/unit/issue_priority_test.rb

@@ -156,4 +156,20 @@ class IssuePriorityTest < ActiveSupport::TestCase
     IssuePriority.find_by_position_name('highest').destroy
     assert_equal %w(lowest default high2 highest), IssuePriority.active.to_a.sort.map(&:position_name)
   end
+
+  def test_high_should_return_false_when_no_default_priority_and_no_active_priorities
+    IssuePriority.update_all(active: false, is_default: false)
+    priority = IssuePriority.order(:position).last # Highest priority
+    assert_nothing_raised do
+      assert_equal false, priority.high?
+    end
+  end
+
+  def test_low_should_return_false_when_no_default_priority_and_no_active_priorities
+    IssuePriority.update_all(active: false, is_default: false)
+    priority = IssuePriority.order(:position).first # Lowest priority
+    assert_nothing_raised do
+      assert_equal false, priority.low?
+    end
+  end
 end