diff --exclude-from=Zend_Form_diff_ignore --ignore-space-change -ruN library.original/Zend/Form/Decorator/FormElements.php library/Zend/Form/Decorator/FormElements.php
--- library.original/Zend/Form/Decorator/FormElements.php	2010-01-06 03:05:09.000000000 +0100
+++ library/Zend/Form/Decorator/FormElements.php	2010-03-04 14:43:42.000000000 +0100
@@ -85,14 +85,14 @@
                  ->setTranslator($translator);
             if ($item instanceof Zend_Form_Element) {
                 $item->setBelongsTo($belongsTo);
-            } elseif (!empty($belongsTo) && ($item instanceof Zend_Form)) {
+            } elseif (null !== $belongsTo && ($item instanceof Zend_Form)) {
                 if ($item->isArray()) {
                     $name = $this->mergeBelongsTo($belongsTo, $item->getElementsBelongTo());
                     $item->setElementsBelongTo($name, true);
                 } else {
                     $item->setElementsBelongTo($belongsTo, true);
                 }
-            } elseif (!empty($belongsTo) && ($item instanceof Zend_Form_DisplayGroup)) {
+            } elseif (null !== $belongsTo && ($item instanceof Zend_Form_DisplayGroup)) {
                 foreach ($item as $element) {
                     $element->setBelongsTo($belongsTo);
                 }
diff --exclude-from=Zend_Form_diff_ignore --ignore-space-change -ruN library.original/Zend/Form.php library/Zend/Form.php
--- library.original/Zend/Form.php	2010-01-06 03:05:09.000000000 +0100
+++ library/Zend/Form.php	2010-03-04 15:25:11.000000000 +0100
@@ -842,7 +842,7 @@
     public function setName($name)
     {
         $name = $this->filterName($name);
-        if (('0' !== $name) && empty($name)) {
+        if ('' === $name) {
             require_once 'Zend/Form/Exception.php';
             throw new Zend_Form_Exception('Invalid name provided; must contain only valid variable characters and be non-empty');
         }
@@ -1397,7 +1397,7 @@
     {
         $origName = $this->getElementsBelongTo();
         $name = $this->filterName($array, true);
-        if (empty($name)) {
+        if ('' === $name) {
             $name = null;
         }
         $this->_elementsBelongTo = $name;
@@ -1449,7 +1449,7 @@
     {
         if ((null === $this->_elementsBelongTo) && $this->isArray()) {
             $name = $this->getName();
-            if (!empty($name)) {
+            if (null !== $name) {
                 return $name;
             }
         }
@@ -1742,7 +1742,7 @@
     {
         if (null === $name) {
             $name = $group->getName();
-            if (empty($name)) {
+            if ('' === $name) {
                 require_once 'Zend/Form/Exception.php';
                 throw new Zend_Form_Exception('Invalid display group added; requires name');
             }
@@ -2293,7 +2293,7 @@
         $arrayKeys = array();
         foreach ($this->getSubForms() as $key => $subForm) {
             $array = $this->_getArrayName($subForm->getElementsBelongTo());
-            if (!empty($array)) {
+            if (null !== $array) {
                 if ($name == $array) {
                     return $subForm->getMessages(null, true);
                 }
@@ -2320,7 +2320,7 @@
             if (!empty($fMessages)) {
                 if (array_key_exists($key, $arrayKeys)) {
                     $fMessages = $this->_attachToArray($fMessages, $arrayKeys[$key]);
-                    $messages = array_merge($messages, $fMessages);
+					$messages += $fMessages; // array union instead of array_merge to prevent shuffling numeric form names
                 } else {
                     $messages[$key] = $fMessages;
                 }