Bug #1599782: Fix segfault on bsddb.db.DB().type().

The problem is that _DB_get_type() can't be called without the GIL
because it calls a bunch of PyErr_* APIs when an error occurs.
There were no other cases in this file that it was called without the GIL.
Removing the BEGIN/END THREAD around _DB_get_type() made everything work.

Will backport.

Lib/bsddb/test/test_dbobj.py

@@ -69,6 +69,10 @@ def test02_dbobj_dict_interface(self):
         self.db.close()
         self.env.close()
 
+    def test03_dbobj_type_before_open(self):
+	# Ensure this doesn't cause a segfault.
+	self.assertRaises(db.DBInvalidArgError, db.DB().type)
+
 #----------------------------------------------------------------------
 
 def test_suite():

Misc/NEWS

@@ -242,6 +242,8 @@ Extension Modules
   a2b_qp() function, instead leave it in the string as quopri.decode()
   does.
 
+- Bug #1599782: Fix segfault on bsddb.db.DB().type().
+
 - Bug #1567666: Emulate GetFileAttributesExA for Win95.
 
 - Patch #1576166: Support os.utime for directories on Windows NT+.

Modules/_bsddb.c

@@ -1779,9 +1779,7 @@ DB_get_type(DBObject* self, PyObject* args)
         return NULL;
     CHECK_DB_NOT_CLOSED(self);
 
-    MYDB_BEGIN_ALLOW_THREADS;
     type = _DB_get_type(self);
-    MYDB_END_ALLOW_THREADS;
     if (type == -1)
         return NULL;
     return PyInt_FromLong(type);