Fix dirty checking handling broken by #1232

Author: graemerocher

grails-datastore-core/src/main/groovy/org/grails/datastore/mapping/dirty/checking/DirtyCheckable.groovy

@@ -80,7 +80,7 @@ trait DirtyCheckable {
             def oldValue = ((GroovyObject) this).getProperty(propertyName)
             if ((newValue == null && oldValue != null) ||
                 (newValue != null && oldValue == null) ||
-                (newValue && !newValue.equals(oldValue))) {
+                (newValue != null && !newValue.equals(oldValue))) {
                 $changedProperties.put propertyName, oldValue
             }
         }
@@ -95,7 +95,7 @@ trait DirtyCheckable {
         if( $changedProperties != null && !$changedProperties.containsKey(propertyName))  {
             if ((newValue == null && oldValue != null) ||
                 (newValue != null && oldValue == null) ||
-                (newValue && !newValue.equals(oldValue))) {
+                (newValue != null && !newValue.equals(oldValue))) {
                 $changedProperties.put propertyName, oldValue
             }
         }

grails-datastore-core/src/test/groovy/org/grails/datastore/mapping/dirty/checking/DirtyCheckableSpec.groovy

@@ -33,6 +33,36 @@ class DirtyCheckableSpec extends Specification {
         person.hasChanged('lastViewedPost')
         person.getOriginalValue('lastViewedPost').equals(blogPost)
     }
+
+    def 'setting a field that is a boolean dirty checks properly'() {
+        given: 'a class with a boolean property'
+        def animal = new Animal()
+        animal.trackChanges()
+
+        when:"A boolean property is changed"
+        animal.barks = true
+        animal.markDirty("barks", true, false)
+
+        then:"the property changed"
+        animal.barks
+        animal.hasChanged()
+        animal.hasChanged("barks")
+
+        when:"it is set to false"
+        animal.trackChanges() // reset
+        animal.barks = false
+        animal.markDirty("barks", false, true)
+
+        then:"the property changed"
+        !animal.barks
+        animal.hasChanged()
+        animal.hasChanged("barks")
+
+    }
+}
+
+class Animal implements DirtyCheckable {
+    boolean barks
 }
 
 class Person implements DirtyCheckable {