[6.1/trunk] wrong check : Cannot change the category of existing UoM; patch included

Try to import several time this UOM CSV file (for instance using the GTK client)

After first importation, subsequent importations will fail (silently, you might want to hack the GTK client to actually make it print the server warning message, this is yet an other GTK bug)
So if you hack the GTK client to display the message, then you'll see the server error response:
(-1, {'category_id': 1, 'name': 'toto', 'factor': 1.0}, u"Line 1 : Warning\nCannot change the category of existing UoM 'toto3'.", '')

If you look in product/product.py, the test of UOM category change is plain wrong:

    def write(self, cr, uid, ids, vals, context=None):
        if 'category_id' in vals:
            for uom in self.browse(cr, uid, ids, context=context):
                if uom.category_id != vals['category_id']:
                    raise osv.except_osv(_('Warning'),_("Cannot change the category of existing UoM '%s'.") % (uom.name,))

You are comparing a browse object to an integer...

Of course this should be instead:

    def write(self, cr, uid, ids, vals, context=None):
        if 'category_id' in vals:
            for uom in self.browse(cr, uid, ids, context=context):
                if uom.category_id.id != vals['category_id']:
                    raise osv.except_osv(_('Warning'),_("Cannot change the category of existing UoM '%s'.") % (uom.name,))

Thanks to change that...