GRAILS-7031 - improve the handling of the default attribute on the g:message tag. specifically, if the default value was an empty string it wasn't being respected.

Author: jeffscottbrown

src/java/org/codehaus/groovy/grails/plugins/web/taglib/ValidationTagLib.groovy

@@ -283,7 +283,12 @@ class ValidationTagLib {
         else if (attrs.code) {
             def code = attrs.code
             def args = attrs.args
-            def defaultMessage = attrs['default'] ?: code
+            def defaultMessage
+			if(attrs.containsKey('default')) {
+				defaultMessage = attrs['default']
+			} else {
+				defaultMessage = code
+			}
 
             def message = messageSource.getMessage(code, args == null ? null : args.toArray(),
                 defaultMessage, locale)

src/test/org/codehaus/groovy/grails/web/taglib/ValidationTagLibTests.groovy

@@ -379,6 +379,11 @@ enum Title implements org.springframework.context.MessageSourceResolvable {
 
         assertOutputEquals("The Default Message", template, [message: resolvable])
     }
+	
+	void testDefaultMessageAttribute() {
+		def template  = '<g:message code="my.message.code" default=""/>'
+		assertOutputEquals "", template
+	}
 
     void testFieldValueTagWithMessageSourceResolvablePropertyUsesDefaultMessage() {
         def Title = ga.getClassForName("Title")