Merge lp:~openerp-commiter/openobject-server/read_group_NULL_value-nch into lp:openobject-server/6.0

[Naresh(OpenERP)]

[FIX] backported from trunk revision:3900 read_group: NULL->False for grouped boolean fields We need to coalesce NULLs to False when grouping boolean fields, otherwise we get duplicate groups sharing the same rows.

=== modified file 'bin/osv/orm.py'
--- bin/osv/orm.py	2011-12-15 12:10:30 +0000
+++ bin/osv/orm.py	2012-01-12 11:14:25 +0000
@@ -2179,10 +2179,13 @@
         group_count = group_by = groupby
         if groupby:
             if fget.get(groupby):
-                if fget[groupby]['type'] in ('date', 'datetime'):
-                    flist = "to_char(%s,'yyyy-mm') as %s " % (qualified_groupby_field, groupby)
-                    groupby = "to_char(%s,'yyyy-mm')" % (qualified_groupby_field)
-                    qualified_groupby_field = groupby
+                groupby_type = fget[groupby]['type']
+                if groupby_type in ('date', 'datetime'):    
+                    qualified_groupby_field = "to_char(%s,'yyyy-mm')" % qualified_groupby_field
+                    flist = "%s as %s " % (qualified_groupby_field, groupby)
+                elif groupby_type == 'boolean':
+                     qualified_groupby_field = "coalesce(%s,false)" % qualified_groupby_field
+                     flist = "%s as %s " % (qualified_groupby_field, groupby)
                 else:
                     flist = qualified_groupby_field
             else: