Fixes bug 477182 on pybsddb.sf.net. DB objects now load the flags and

pay attention to them when opening an existing database.  This means
that d[] behaves properly even on databases previously created with DB_DUP
or DB_DUPSORT flags to allow duplicate keys.

http://sourceforge.net/tracker/index.php?func=detail&aid=477182&group_id=13900&atid=113900

Do not backport, this bugfix could be considered an API change.

Lib/bsddb/test/test_misc.py

@@ -90,6 +90,30 @@ class MiscTestCase(unittest.TestCase):
             db1.close()
             os.unlink(self.filename)
 
+    def test_DB_set_flags_persists(self):
+        try:
+            db1 = db.DB()
+            db1.set_flags(db.DB_DUPSORT)
+            db1.open(self.filename, db.DB_HASH, db.DB_CREATE)
+            db1['a'] = 'eh'
+            db1['a'] = 'A'
+            self.assertEqual([('a', 'A')], db1.items())
+            db1.put('a', 'Aa')
+            self.assertEqual([('a', 'A'), ('a', 'Aa')], db1.items())
+            db1.close()
+            db1 = db.DB()
+            # no set_flags call, we're testing that it reads and obeys
+            # the flags on open.
+            db1.open(self.filename, db.DB_HASH)
+            self.assertEqual([('a', 'A'), ('a', 'Aa')], db1.items())
+            # if it read the flags right this will replace all values
+            # for key 'a' instead of adding a new one.  (as a dict should)
+            db1['a'] = 'new A'
+            self.assertEqual([('a', 'new A')], db1.items())
+        finally:
+            db1.close()
+            os.unlink(self.filename)
+
 
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