Fix bug #1413192, fix seg fault in bsddb if a txn was deleted before the env.

Will backport.

Lib/bsddb/test/test_1413192.py

+
+# http://python.org/sf/1413192
+#
+# This test relies on the variable names, see the bug report for details.
+# The problem was that the env was deallocated prior to the txn.
+
+from bsddb import db
+
+env_name = '.'
+
+env = db.DBEnv()
+env.open(env_name, db.DB_CREATE | db.DB_INIT_TXN)
+the_txn = env.txn_begin()
+
+map = db.DB(env)
+map.open('xxx.db', "p", db.DB_HASH, db.DB_CREATE, 0666, txn=the_txn)

Lib/bsddb/test/test_all.py

@@ -46,6 +46,12 @@ test_all.verbose = verbose
 
 
 def suite():
+    try:
+        # this is special, it used to segfault the interpreter
+        import test_1413192
+    except:
+        pass
+
     test_modules = [
         'test_associate',
         'test_basics',

Lib/test/test_bsddb3.py

@@ -22,6 +22,12 @@ if 'silent' in sys.argv:  # take care of old flag, just in case
 
 
 def suite():
+    try:
+        # this is special, it used to segfault the interpreter
+        import bsddb.test.test_1413192
+    except:
+        pass
+
     test_modules = [
         'test_associate',
         'test_basics',

Misc/NEWS

@@ -216,6 +216,9 @@ Core and builtins
 Extension Modules
 -----------------
 
+- Bug #1413192, fix seg fault in bsddb if a transaction was deleted
+  before the env.
+
 - Patch #1103116: Basic AF_NETLINK support.
 
 - Bug #1402308, (possible) segfault when using mmap.mmap(-1, ...)

Modules/_bsddb.c

@@ -266,6 +266,7 @@ typedef struct {
 typedef struct {
     PyObject_HEAD
     DB_TXN*         txn;
+    PyObject        *env;
 #ifdef HAVE_WEAKREF
     PyObject        *in_weakreflist; /* List of weak references */
 #endif
@@ -928,6 +929,8 @@ newDBTxnObject(DBEnvObject* myenv, DB_TXN *parent, int flags)
     DBTxnObject* self = PyObject_New(DBTxnObject, &DBTxn_Type);
     if (self == NULL)
         return NULL;
+    Py_INCREF(myenv);
+    self->env = (PyObject*)myenv;
 #ifdef HAVE_WEAKREF
     self->in_weakreflist = NULL;
 #endif
@@ -938,11 +941,10 @@ newDBTxnObject(DBEnvObject* myenv, DB_TXN *parent, int flags)
 #else
     err = txn_begin(myenv->db_env, parent, &(self->txn), flags);
 #endif
-    /* TODO add a weakref(self) to the self->myenvobj->open_child_weakrefs
-     * list so that a DBEnv can refuse to close without aborting any open
-     * open DBTxns and closing any open DBs first. */
     MYDB_END_ALLOW_THREADS;
     if (makeDBError(err)) {
+        Py_DECREF(self->env);
+        PyObject_Del(self);
         self = NULL;
     }
     return self;
@@ -973,6 +975,7 @@ DBTxn_dealloc(DBTxnObject* self)
     }
 #endif
 
+    Py_DECREF(self->env);
     PyObject_Del(self);
 }