Conflict:

--- a/addons/mrp/mrp.py
+++ b/addons/mrp/mrp.py
@@@ -263,11 -263,11 +263,19 @@@ class mrp_bom(osv.osv)
              for bom in boms:
                  if bom.product_id.id in all_prod:
                      return False
++<<<<<<< HEAD
 +                lines = bom.bom_lines
 +                if lines:
 +                    res = res and check_bom([bom_id for bom_id in lines if bom_id not in boms], all_prod + [bom.product_id.id])
 +            return res
 +        return check_bom(boms, [])
++=======
+                 if bom.bom_lines:
+                     res = res and check_bom([b for b in bom.bom_lines if b not in boms], all_prod + [bom.product_id.id])
+             return res
+         return check_bom(boms, [])
+ 
++>>>>>>> odoo/7.0
  
      _constraints = [
          (_check_recursion, 'Error ! You cannot create recursive BoM.', ['parent_id']),

Resolved as:

--- a/addons/mrp/mrp.py
+++ b/addons/mrp/mrp.py
@@ -263,9 +263,8 @@ class mrp_bom(osv.osv):
             for bom in boms:
                 if bom.product_id.id in all_prod:
                     return False
-                lines = bom.bom_lines
-                if lines:
-                    res = res and check_bom([bom_id for bom_id in lines if bom_id not in boms], all_prod + [bom.product_id.id])
+                if bom.bom_lines:
+                    res = res and check_bom([b for b in bom.bom_lines if b not in boms], all_prod + [bom.product_id.id])
             return res
         return check_bom(boms, [])

This is an equivalent fix for https://bugs.launchpad.net/ocb-addons/+bug/1155569. Reverting github.com/OCA/OCB@3ec0353d in favour of github.com/odoo/odoo@49e7e67a27

Committed as github.com/OCA/OCB@44a0c76063 by @StefanRijnhart