From: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Date: Sat, 10 May 2025 22:37:17 +0000 (+0100)
Subject: gh-132983: Make zstd types immutable (#133784)
X-Git-Tag: v3.15.0a1~1766
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a87b6e9ae6da255f30465ed59a78913ebf2e898;p=thirdparty%2FPython%2Fcpython.git

gh-132983: Make zstd types immutable (#133784)
---

diff --git a/Modules/_zstd/_zstdmodule.c b/Modules/_zstd/_zstdmodule.c
index bddef0d0b864..c3852fe89732 100644
--- a/Modules/_zstd/_zstdmodule.c
+++ b/Modules/_zstd/_zstdmodule.c
@@ -679,6 +679,9 @@ do {                                                                         \
     ADD_INT_CONST_TO_TYPE(mod_state->ZstdCompressor_type,
                           "FLUSH_FRAME", ZSTD_e_end);
 
+    /* Make ZstdCompressor immutable (set Py_TPFLAGS_IMMUTABLETYPE) */
+    PyType_Freeze(mod_state->ZstdCompressor_type);
+
 #undef ADD_TYPE
 #undef ADD_INT_MACRO
 #undef ADD_ZSTD_COMPRESSOR_INT_CONST
diff --git a/Modules/_zstd/compressor.c b/Modules/_zstd/compressor.c
index e70eb637b29f..355a27d2734a 100644
--- a/Modules/_zstd/compressor.c
+++ b/Modules/_zstd/compressor.c
@@ -729,6 +729,9 @@ static PyType_Slot zstdcompressor_slots[] = {
 PyType_Spec zstd_compressor_type_spec = {
     .name = "compression.zstd.ZstdCompressor",
     .basicsize = sizeof(ZstdCompressor),
+    // Py_TPFLAGS_IMMUTABLETYPE is not used here as several
+    // associated constants need to be added to the type.
+    // PyType_Freeze is called later to set the flag.
     .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
     .slots = zstdcompressor_slots,
 };
diff --git a/Modules/_zstd/decompressor.c b/Modules/_zstd/decompressor.c
index 2ed88cd3f231..a654a9540e1f 100644
--- a/Modules/_zstd/decompressor.c
+++ b/Modules/_zstd/decompressor.c
@@ -902,6 +902,7 @@ static PyType_Slot ZstdDecompressor_slots[] = {
 PyType_Spec zstd_decompressor_type_spec = {
     .name = "compression.zstd.ZstdDecompressor",
     .basicsize = sizeof(ZstdDecompressor),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE
+             | Py_TPFLAGS_HAVE_GC,
     .slots = ZstdDecompressor_slots,
 };
diff --git a/Modules/_zstd/zstddict.c b/Modules/_zstd/zstddict.c
index 99976cef85a2..47bc8a84ca24 100644
--- a/Modules/_zstd/zstddict.c
+++ b/Modules/_zstd/zstddict.c
@@ -278,6 +278,7 @@ static PyType_Slot zstddict_slots[] = {
 PyType_Spec zstd_dict_type_spec = {
     .name = "compression.zstd.ZstdDict",
     .basicsize = sizeof(ZstdDict),
-    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+    .flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE
+             | Py_TPFLAGS_HAVE_GC,
     .slots = zstddict_slots,
 };