Issue #21639: Fix a division by zero in tracemalloc on calloc(0, 0). The
regression was introduced recently with the introduction of the new "calloc"
functions (PyMem_RawCalloc, PyMem_Calloc, PyObject_Calloc).
Add also a unit test to check for the non-regression.
diff --git a/Lib/test/test_tracemalloc.py b/Lib/test/test_tracemalloc.py
index c953885..33b0dc2 100644
--- a/Lib/test/test_tracemalloc.py
+++ b/Lib/test/test_tracemalloc.py
@@ -807,6 +807,12 @@
b'number of frames',
stderr)
+ def test_pymem_alloc0(self):
+ # Issue #21639: Check that PyMem_Malloc(0) with tracemalloc enabled
+ # does not crash.
+ code = 'import _testcapi; _testcapi.test_pymem_alloc0(); 1'
+ assert_python_ok('-X', 'tracemalloc', '-c', code)
+
def test_main():
support.run_unittest(
diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
index 429b209..1e45414 100644
--- a/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@ -478,7 +478,7 @@
PyMemAllocator *alloc = (PyMemAllocator *)ctx;
void *ptr;
- assert(nelem <= PY_SIZE_MAX / elsize);
+ assert(elsize == 0 || nelem <= PY_SIZE_MAX / elsize);
if (use_calloc)
ptr = alloc->calloc(alloc->ctx, nelem, elsize);