bpo-24596: Decref module in PyRun_SimpleFileExFlags() on SystemExit (GH-7918) (GH-8069)

miss-islington · ZackerySpytz · pitrou · commit e1ebf51f7603 · 2018-07-03T22:17:46.000+02:00
PyErr_Print() will not return when the exception is a SystemExit, so decref the __main__ module object in that case. (cherry picked from commit d8cba5d) Co-authored-by: Zackery Spytz <zspytz@gmail.com>
diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
@@ -1,7 +1,7 @@
 import unittest
 from test.support import (verbose, refcount_test, run_unittest,
                           strip_python_stderr, cpython_only, start_threads,
-                          temp_dir, requires_type_collecting)
+                          temp_dir, requires_type_collecting, TESTFN, unlink)
 from test.support.script_helper import assert_python_ok, make_script
 
 import sys
@@ -713,6 +713,21 @@ def __del__(self):
             rc, out, err = assert_python_ok('-c', code)
             self.assertEqual(out.strip(), b'__del__ called')
 
+    @requires_type_collecting
+    def test_global_del_SystemExit(self):
+        code = """if 1:
+            class ClassWithDel:
+                def __del__(self):
+                    print('__del__ called')
+            a = ClassWithDel()
+            a.link = a
+            raise SystemExit(0)"""
+        self.addCleanup(unlink, TESTFN)
+        with open(TESTFN, 'w') as script:
+            script.write(code)
+        rc, out, err = assert_python_ok(TESTFN)
+        self.assertEqual(out.strip(), b'__del__ called')
+
     def test_get_stats(self):
         stats = gc.get_stats()
         self.assertEqual(len(stats), 3)
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-06-25-16-54-05.bpo-24596.Rkwova.rst b/Misc/NEWS.d/next/Core and Builtins/2018-06-25-16-54-05.bpo-24596.Rkwova.rst
@@ -0,0 +1,2 @@
+Decref the module object in :c:func:`PyRun_SimpleFileExFlags` before calling
+:c:func:`PyErr_Print()`.  Patch by Zackery Spytz.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
@@ -421,6 +421,7 @@ PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit,
     }
     flush_io();
     if (v == NULL) {
+        Py_CLEAR(m);
         PyErr_Print();
         goto done;
     }
@@ -429,7 +430,7 @@ PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit,
   done:
     if (set_file_name && PyDict_DelItemString(d, "__file__"))
         PyErr_Clear();
-    Py_DECREF(m);
+    Py_XDECREF(m);
     return ret;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Decref the module object in :c:func:`PyRun_SimpleFileExFlags` before calling
	`2`	+:c:func:`PyErr_Print()`. Patch by Zackery Spytz.
Original file line number	Diff line number	Diff line change
`@@ -421,6 +421,7 @@ PyRun_SimpleFileExFlags(FILE fp, const char filename, int closeit,`
`421`	`421`	`}`
`422`	`422`	`flush_io();`
`423`	`423`	`if (v == NULL) {`
	`424`	`+ Py_CLEAR(m);`
`424`	`425`	`PyErr_Print();`
`425`	`426`	`goto done;`
`426`	`427`	`}`
`@@ -429,7 +430,7 @@ PyRun_SimpleFileExFlags(FILE fp, const char filename, int closeit,`
`429`	`430`	`done:`
`430`	`431`	`if (set_file_name && PyDict_DelItemString(d, "__file__"))`
`431`	`432`	`PyErr_Clear();`
`432`		`- Py_DECREF(m);`
	`433`	`+ Py_XDECREF(m);`
`433`	`434`	`return ret;`
`434`	`435`	`}`
`435`	`436`