gh-132983: Call Py_XDECREF rather than PyObject_GC_Del in failed __new__ (GH-133962)

encukou · web-flow · commit e575190abbd9 · 2025-05-13T11:11:52.000+02:00
Call Py_XDECREF rather than PyObject_GC_Del in failed __new__

This will call tp_dealloc and clear all members.
diff --git a/Modules/_zstd/compressor.c b/Modules/_zstd/compressor.c
@@ -338,6 +338,7 @@ _zstd_ZstdCompressor_new_impl(PyTypeObject *type, PyObject *level,
     }
 
     self->use_multithread = 0;
+    self->dict = NULL;
 
     /* Compression context */
     self->cctx = ZSTD_createCCtx();
@@ -372,7 +373,6 @@ _zstd_ZstdCompressor_new_impl(PyTypeObject *type, PyObject *level,
     }
 
     /* Load Zstandard dictionary to compression context */
-    self->dict = NULL;
     if (zstd_dict != Py_None) {
         if (_zstd_load_c_dict(self, zstd_dict) < 0) {
             goto error;
@@ -387,9 +387,7 @@ _zstd_ZstdCompressor_new_impl(PyTypeObject *type, PyObject *level,
     return (PyObject*)self;
 
 error:
-    if (self != NULL) {
-        PyObject_GC_Del(self);
-    }
+    Py_XDECREF(self);
     return NULL;
 }
 
@@ -401,7 +399,9 @@ ZstdCompressor_dealloc(PyObject *ob)
     PyObject_GC_UnTrack(self);
 
     /* Free compression context */
-    ZSTD_freeCCtx(self->cctx);
+    if (self->cctx) {
+        ZSTD_freeCCtx(self->cctx);
+    }
 
     /* Py_XDECREF the dict after free the compression context */
     Py_CLEAR(self->dict);
diff --git a/Modules/_zstd/decompressor.c b/Modules/_zstd/decompressor.c
@@ -554,6 +554,7 @@ _zstd_ZstdDecompressor_new_impl(PyTypeObject *type, PyObject *zstd_dict,
     self->in_end = -1;
     self->unused_data = NULL;
     self->eof = 0;
+    self->dict = NULL;
 
     /* needs_input flag */
     self->needs_input = 1;
@@ -570,7 +571,6 @@ _zstd_ZstdDecompressor_new_impl(PyTypeObject *type, PyObject *zstd_dict,
     }
 
     /* Load Zstandard dictionary to decompression context */
-    self->dict = NULL;
     if (zstd_dict != Py_None) {
         if (_zstd_load_d_dict(self, zstd_dict) < 0) {
             goto error;
@@ -592,9 +592,7 @@ _zstd_ZstdDecompressor_new_impl(PyTypeObject *type, PyObject *zstd_dict,
     return (PyObject*)self;
 
 error:
-    if (self != NULL) {
-        PyObject_GC_Del(self);
-    }
+    Py_XDECREF(self);
     return NULL;
 }
 
@@ -606,7 +604,9 @@ ZstdDecompressor_dealloc(PyObject *ob)
     PyObject_GC_UnTrack(self);
 
     /* Free decompression context */
-    ZSTD_freeDCtx(self->dctx);
+    if (self->dctx) {
+        ZSTD_freeDCtx(self->dctx);
+    }
 
     /* Py_CLEAR the dict after free decompression context */
     Py_CLEAR(self->dict);
diff --git a/Modules/_zstd/zstddict.c b/Modules/_zstd/zstddict.c
@@ -52,6 +52,7 @@ _zstd_ZstdDict_new_impl(PyTypeObject *type, PyObject *dict_content,
 
     self->dict_content = NULL;
     self->d_dict = NULL;
+    self->dict_id = 0;
 
     /* ZSTD_CDict dict */
     self->c_dicts = PyDict_New();
@@ -92,9 +93,7 @@ _zstd_ZstdDict_new_impl(PyTypeObject *type, PyObject *dict_content,
     return (PyObject*)self;
 
 error:
-    if (self != NULL) {
-        PyObject_GC_Del(self);
-    }
+    Py_XDECREF(self);
     return NULL;
 }
 
@@ -106,7 +105,9 @@ ZstdDict_dealloc(PyObject *ob)
     PyObject_GC_UnTrack(self);
 
     /* Free ZSTD_DDict instance */
-    ZSTD_freeDDict(self->d_dict);
+    if (self->d_dict) {
+        ZSTD_freeDDict(self->d_dict);
+    }
 
     /* Release dict_content after Free ZSTD_CDict/ZSTD_DDict instances */
     Py_CLEAR(self->dict_content);
