[FIX] osv: binary size already in human format

In version 8.0, postgresql's pg_size_pretty function is used
(http://www.postgresql.org/docs/9.4/static/functions-admin.html) when
getting the size of a binary field when reading if `bin_size`
or `bin_size_[col_name]` is set in the context.

So in 8.0 the size of a binary field get units bytes, kB, MB, GB and TB
which was not taken into account. e.g: '5.3 GB'.

This fix uses the size of the string to choose to differenciate the two.

e.g: '10000 bytes' (the longest size) will be returned directly, but
for something longer the human size of the content length will be
returned.

There is a corner case if a file is shorter than 12 bytes but
it is an enough of a small scenario with small implications that it is
deemed acceptable.

closes #7485
opw-644085

openerp/addons/base/ir/ir_attachment.py

@@ -162,9 +162,6 @@ class ir_attachment(osv.osv):
                 result[attach.id] = self._file_read(cr, uid, attach.store_fname, bin_size)
             else:
                 result[attach.id] = attach.db_datas
-                if bin_size:
-                    result[attach.id] = int(result[attach.id] or 0)
-
         return result
 
     def _data_set(self, cr, uid, id, name, value, arg, context=None):

openerp/osv/fields.py

@@ -1069,6 +1069,8 @@ def get_nice_size(value):
         size = value
     elif value: # this is supposed to be a string
         size = len(value)
+        if size < 12:  # suppose human size
+            return value
     return tools.human_size(size)
 
 # See http://www.w3.org/TR/2000/REC-xml-20001006#NT-Char