Comment 1 for bug 700451

Reported by Dr. Ferdinand Gassauer:
 "constraints can not be altered ..."

Indeed, when we define an expression like

class bar(osv.osv):
  _inherit = 'bar.bar'

  def _check_foo(self, cr, uid, ids, context):
      return True

  _constraints = [ (_check_foo, "Foo failed!", ['foo']) ]

... it means that _check_foo will be passed as an *object* to the model's
structure of _constraints. Therefore, it would be unequal and just append
the list of any existing constraints. So, an older (_check_foo, , ['foo'])
would always remain active using the previous code. This has to do with
the _check_foo being an unbound (ie. not inheritable) function.

Now, we check the /string name/ of the function, too. We say that if the
inherited class's constraint function has the same name "_check_foo", the
old ones shall be replaced.

Note: this MAY introduce unpredictable results, if several modules try
to override the same inherited constraint. There is no guaranteed order
of inheritance. Please avoid using this feature unless necessary.
---
 bin/osv/osv.py | 7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/bin/osv/osv.py b/bin/osv/osv.py
index 411dc0f..21a7e05 100644
--- a/bin/osv/osv.py
+++ b/bin/osv/osv.py
@@ -372,7 +372,12 @@ class osv(osv_base, orm.orm):
                                 exist = False
                                 for c2 in range(len(new)):
                                      #For _constraints, we should check field and methods as well
- if new[c2][2]==c[2] and new[c2][0]==c[0]:
+ if new[c2][2]==c[2] and (new[c2][0] == c[0] \
+ or getattr(new[c2][0],'__name__', True) == \
+ getattr(c[0],'__name__', False)):
+ # If new class defines a constraint with
+ # same function name, we let it override
+ # the old one.
                                         new[c2] = c
                                         exist = True
                                         break
--
1.7.1