Issue #21951: Fixed a crash in Tkinter on AIX when called Tcl command with
empty string or tuple argument.
On some platforms Tcl memory allocator returns NULL when allocating zero-sized
block of memory.
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
index 7485e58..da8f629 100644
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tcl.py
@@ -416,7 +416,6 @@
self.assertEqual(passValue((1, '2', (3.4,))),
(1, '2', (3.4,)) if self.wantobjects else '1 2 3.4')
- @unittest.skipIf(sys.platform.startswith("aix"), 'Issue #21951: crashes on AIX')
def test_user_command(self):
result = None
def testfunc(arg):
@@ -444,9 +443,11 @@
check('string')
check('string\xbd')
check('string\u20ac')
+ check('')
check(b'string', 'string')
check(b'string\xe2\x82\xac', 'string\xe2\x82\xac')
check(b'string\xbd', 'string\xbd')
+ check(b'', '')
check('str\x00ing')
check('str\x00ing\xbd')
check('str\x00ing\u20ac')
diff --git a/Misc/NEWS b/Misc/NEWS
index 6668877..dddcf76 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -32,6 +32,9 @@
Library
-------
+- Issue #21951: Fixed a crash in Tkinter on AIX when called Tcl command with
+ empty string or tuple argument.
+
- Issue #21951: Tkinter now most likely raises MemoryError instead of crash
if the memory allocation fails.
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 7871dec..6d777d3 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -899,6 +899,8 @@
Py_ssize_t size, i;
size = PyTuple_Size(value);
+ if (size == 0)
+ return Tcl_NewListObj(0, NULL);
if (!CHECK_SIZE(size, sizeof(Tcl_Obj *))) {
PyErr_SetString(PyExc_OverflowError, "tuple is too long");
return NULL;
@@ -925,6 +927,8 @@
inbuf = PyUnicode_DATA(value);
size = PyUnicode_GET_LENGTH(value);
+ if (size == 0)
+ return Tcl_NewUnicodeObj((const void *)"", 0);
if (!CHECK_SIZE(size, sizeof(Tcl_UniChar))) {
PyErr_SetString(PyExc_OverflowError, "string is too long");
return NULL;