Fix memory leak in PyTypeBuilder::build

PyO3 · Aug 18, 2023 · 00d3507 · 00d3507
1 parent 7f32ed9
commit 00d3507
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diff --git a/newsfragments/3400.fixed.md b/newsfragments/3400.fixed.md
@@ -0,0 +1 @@
+Fix memory leak in `PyTypeBuilder::build`.
diff --git a/src/pyclass/create_type_object.rs b/src/pyclass/create_type_object.rs
@@ -372,8 +372,9 @@ impl PyTypeBuilder {
         // Safety: python expects this empty slot
         unsafe { self.push_slot(0, ptr::null_mut::<c_void>()) }
 
+        let name = py_class_qualified_name(module_name, name)?;
         let mut spec = ffi::PyType_Spec {
-            name: py_class_qualified_name(module_name, name)?,
+            name,
             basicsize: basicsize as c_int,
             itemsize: 0,
 
@@ -386,6 +387,8 @@ impl PyTypeBuilder {
         // Safety: We've correctly setup the PyType_Spec at this point
         let type_object: Py<PyType> =
             unsafe { Py::from_owned_ptr_or_err(py, ffi::PyType_FromSpec(&mut spec))? };
+        // Safety: `name` is a valid pointer obtained from `CString::into_raw` in `py_class_qualified_name`
+        drop(unsafe { CString::from_raw(name) });
 
         for cleanup in std::mem::take(&mut self.cleanup) {
             cleanup(&self, type_object.as_ref(py).as_type_ptr());