diff --git a/trytond/ir/translation.xml b/trytond/ir/translation.xml
index 8ad18e5222..9a95fd10ba 100644
--- a/trytond/ir/translation.xml
+++ b/trytond/ir/translation.xml
@@ -124,6 +124,15 @@ this repository contains the full copyright notices and license terms. -->
             <field name="module">ir</field>
             <field name="fuzzy" eval="False"/>
         </record>
+        <record model="ir.translation" id="translation_size_validation_record">
+            <field name="name">size_validation_record</field>
+            <field name="lang">en_US</field>
+            <field name="type">error</field>
+            <field name="src">The field "%s" on "%s" is too long.</field>
+            <field name="value">The field "%s" on "%s" is too long.</field>
+            <field name="module">ir</field>
+            <field name="fuzzy" eval="False"/>
+        </record>
         <record model="ir.translation" id="translation_access_error">
             <field name="name">access_error</field>
             <field name="lang">en_US</field>
diff --git a/trytond/model/browse.py b/trytond/model/browse.py
index 59af073f81..91f12b0e16 100644
--- a/trytond/model/browse.py
+++ b/trytond/model/browse.py
@@ -132,7 +132,8 @@ class BrowseRecord(object):
                     elif hasattr(j, 'get_target'):
                         model = j.get_target(self._model.pool)
                     if j._type in ('many2one',):
-                        if not data[i]:
+                        if not data[i] and not (isinstance(data[i], (int, long))
+                                and not isinstance(data[i], type(False))):
                             data[i] = BrowseRecordNull()
                         else:
                             ctx = self._context
@@ -184,7 +185,7 @@ class BrowseRecord(object):
         return hash((self._model_name, self._id))
 
     def __nonzero__(self):
-        return bool(self._id)
+        return True
 
     __repr__ = __str__
 
diff --git a/trytond/model/modelstorage.py b/trytond/model/modelstorage.py
index b61debb349..80d37af688 100644
--- a/trytond/model/modelstorage.py
+++ b/trytond/model/modelstorage.py
@@ -950,6 +950,25 @@ class ModelStorage(Model):
                                         error_args=self._get_error_args(cursor,
                                             user, field_name, context=context),
                                         context=context)
+            # validate required
+            if field.required:
+                for record in records:
+                    if isinstance(record[field_name], (BrowseRecordNull,
+                        type(None), type(False))) and not record[field_name]:
+                        self.raise_user_error(cursor,
+                                'required_validation_record',
+                                error_args=self._get_error_args(cursor,
+                                    user, field_name, context=context),
+                                context=context)
+            # validate size
+            if hasattr(field, 'size') and field.size:
+                for record in records:
+                    if len(record[field_name]) > field.size:
+                        self.raise_user_error(cursor,
+                                'size_validation_record',
+                                error_args=self._get_error_args(cursor,
+                                    user, field_name, context=context),
+                                context=context)
 
     def _clean_defaults(self, defaults):
         vals = {}