Move away from APIs that use borrowed references under the free-threaded build

src/_imaging.c

@@ -4448,5 +4448,9 @@ PyInit__imaging(void) {
         return NULL;
     }
 
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/_imagingcms.c

@@ -1538,5 +1538,9 @@ PyInit__imagingcms(void) {
 
     PyDateTime_IMPORT;
 
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/_imagingft.c

@@ -20,6 +20,7 @@
 
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
+#include "thirdparty/pythoncapi_compat.h"
 #include "libImaging/Imaging.h"
 
 #include <ft2build.h>
@@ -1204,6 +1205,16 @@
 
     num_namedstyles = master->num_namedstyles;
     list_names = PyList_New(num_namedstyles);
+
+    int *list_names_filled = PyMem_Malloc(num_namedstyles * sizeof(int));
+    if (list_names_filled == NULL) {
+        return PyErr_NoMemory();
+    }
+
+    for (int i = 0; i < num_namedstyles; i++) {
+        list_names_filled[i] = 0;
+    }
+
     if (list_names == NULL) {
         FT_Done_MM_Var(library, master);
         return NULL;
@@ -1219,13 +1230,14 @@
         }
 
         for (j = 0; j < num_namedstyles; j++) {
-            if (PyList_GetItem(list_names, j) != NULL) {
+            if (list_names_filled[j]) {
                 continue;
             }
 
             if (master->namedstyle[j].strid == name.name_id) {
                 list_name = Py_BuildValue("y#", name.string, name.string_len);
                 PyList_SetItem(list_names, j, list_name);
+                list_names_filled[j] = 1;
                 break;
             }
         }
@@ -1576,5 +1588,9 @@
         return NULL;
     }
 
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/_imagingmath.c

@@ -290,5 +290,9 @@ PyInit__imagingmath(void) {
         return NULL;
     }
 
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/_imagingmorph.c

@@ -269,5 +269,9 @@ PyInit__imagingmorph(void) {
 
     m = PyModule_Create(&module_def);
 
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/_imagingtk.c

@@ -62,5 +62,10 @@
         Py_DECREF(m);
         return NULL;
     }
+
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/_webp.c

@@ -1005,5 +1005,9 @@ PyInit__webp(void) {
         return NULL;
     }
 
+#ifdef Py_GIL_DISABLED
+    PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
+#endif
+
     return m;
 }

src/encode.c

@@ -25,6 +25,7 @@
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
 
+#include "thirdparty/pythoncapi_compat.h"
 #include "libImaging/Imaging.h"
 #include "libImaging/Gif.h"
 
@@ -671,7 +672,7 @@
         tags_size = PyList_Size(tags);
         TRACE(("tags size: %d\n", (int)tags_size));
         for (pos = 0; pos < tags_size; pos++) {
-            item = PyList_GetItem(tags, pos);
+            item = PyList_GetItemRef(tags, pos);
             if (!PyTuple_Check(item) || PyTuple_Size(item) != 2) {
                 PyErr_SetString(PyExc_ValueError, "Invalid tags list");
                 return NULL;
@@ -703,7 +704,7 @@
 
     num_core_tags = sizeof(core_tags) / sizeof(int);
     for (pos = 0; pos < tags_size; pos++) {
-        item = PyList_GetItem(tags, pos);
+        item = PyList_GetItemRef(tags, pos);
         // We already checked that tags is a 2-tuple list.
         key = PyTuple_GetItem(item, 0);
         key_int = (int)PyLong_AsLong(key);
@@ -721,7 +722,10 @@
         }
 
         if (!is_core_tag) {
-            PyObject *tag_type = PyDict_GetItem(types, key);
+            PyObject *tag_type;
+            if (PyDict_GetItemRef(types, key, &tag_type) == 0) {
+                PyErr_SetString(PyExc_KeyError, "unknown tag type");
+            }
             if (tag_type) {
                 int type_int = PyLong_AsLong(tag_type);
                 if (type_int >= TIFF_BYTE && type_int <= TIFF_DOUBLE) {