broken search on fields.related for simple cases

[Florent]

Hello,

when the related field is used as an alias of another field of the same object, the search is broken.
This is with branch 6.1.

This happens with following context:
 - field is "fields.related"
 - store=False
 - only 1 chained element (field is an alias of another field of the current model)

Example below:

(1) When using the search method with domain [('report_broken', '=', False)] it breaks
(2) with domain [('report_file', '=', False)] it succeeds

class TestRelated(osv.osv):
    _name = 'test.related.bug'

    _columns = {
        'report_rml': fields.char('Main report file path', size=256),
        'report_broken': fields.related('report_rml', type="char", size=256, string='Report file'),
        'report_file': fields.related('report_rml', type="char", size=256, string='Report file', store=True),
    }

TestRelated()