Validation change for Text type attributes.

The call on Mage_Eav_Model_Attribute_Data_Text:67 to empty returns true of a value of "0" is entered, as specified in the PHP spec. This prevents the entry of zero on the backend admin for fields. Zero should be a valid value, as it was in our case.

No unit tests were created, as no unit tests exist currently for the Eav module.

app/code/core/Mage/Eav/Model/Attribute/Data/Text.php

@@ -64,7 +64,7 @@ public function validateValue($value)
             $value = $this->getEntity()->getDataUsingMethod($attribute->getAttributeCode());
         }
 
-        if ($attribute->getIsRequired() && empty($value)) {
+        if ($attribute->getIsRequired() && empty($value) && $value !=='0') {
             $errors[] = Mage::helper('Mage_Eav_Helper_Data')->__('"%s" is a required value.', $label);
         }