GRAILS-11402 - fix data binding problem caused by a request parameter named '_'

Author: jeffscottbrown

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

@@ -241,7 +241,7 @@ class SimpleDataBinder implements DataBinder {
                             def val = source.getPropertyValue key
                             processIndexedProperty obj, metaProperty, descriptor, val, source, listener, errors
                         }
-                    } else if (propName.startsWith('_')) { // boolean special handling
+                    } else if (propName.startsWith('_') && propName.length() > 1) { // boolean special handling
                         def restOfPropertyName = propName[1..-1]
                         if (!source.containsProperty(restOfPropertyName)) {
                             metaProperty = obj.metaClass.getMetaProperty restOfPropertyName

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

@@ -1250,6 +1250,19 @@ class GrailsWebDataBinderSpec extends Specification {
         then:
         holder.album.title == 'Some Album'
     }
+    
+    @Issue('GRAILS-11402')
+    void 'Test binding when the binding source contains the key "_"'() {
+        given:
+        def publisher = new Publisher()
+        
+        when:
+        binder.bind publisher, [_: '', name: 'Some Publisher'] as SimpleMapDataBindingSource
+        
+        then:
+        !publisher.hasErrors()
+        publisher.name == 'Some Publisher'
+    }
 }
 
 @Entity