GRAILS-11472 - fix binding empty strings to fields marked with @Bindi…

…ngFormat

grails-databinding/src/main/groovy/org/grails/databinding/SimpleDataBinder.groovy

@@ -466,7 +466,7 @@ class SimpleDataBinder implements DataBinder {
         def formattedConverter = formattedValueConvertersionHelpers[field.type]
         if (formattedConverter) {
             converter = { SimpleMapDataBindingSource source ->
-                def value = source.getPropertyValue field.name
+                def value = preprocessValue(source.getPropertyValue(field.name))
                 def convertedValue = null
                 if(value != null) {
                     convertedValue = formattedConverter.convert (value, formattingValue)

grails-test-suite-persistence/src/test/groovy/org/codehaus/groovy/grails/orm/GrailsWebDataBinderSpec.groovy

@@ -1263,6 +1263,29 @@ class GrailsWebDataBinderSpec extends Specification {
         !publisher.hasErrors()
         publisher.name == 'Some Publisher'
     }
+
+    @Issue('GRAILS-11472')
+    void 'test binding an empty string to a Date marked with @BindingFormat'() {
+        given:
+        def book = new DataBindingBook()
+
+        when: 'a valid date string is bound'
+        binder.bind book, [datePublished: '11151969'] as SimpleMapDataBindingSource
+
+        then: 'the date is initialized'
+        !book.hasErrors()
+        book.datePublished
+        Calendar.NOVEMBER == book.datePublished.month
+        15 == book.datePublished.date
+        69 == book.datePublished.year
+
+        when: 'an empty string is bound'
+        binder.bind book, [datePublished: ''] as SimpleMapDataBindingSource
+
+        then: 'the date is null'
+        book.datePublished == null
+        !book.hasErrors()
+    }
 }
 
 @Entity