python · AraHaan · Nov 19, 2017 · Nov 19, 2017 · Nov 19, 2017 · Nov 19, 2017
diff --git a/Doc/c-api/concrete.rst b/Doc/c-api/concrete.rst
@@ -114,4 +114,5 @@ Other Objects
    gen.rst
    coro.rst
    datetime.rst
+   zipimporter.rst
 
diff --git a/Doc/c-api/zipimporter.rst b/Doc/c-api/zipimporter.rst
@@ -0,0 +1,33 @@
+.. highlightlang:: c
+
+.. zipimporter:
+
+ZipImporter Objects
+-------------------
+
+Python for the longest of time had an zipimporter that could not be
+subclassed using the C Python API but could in the Python Layer.
+On Python 3.6.4 users can subclass it in their C code as it is an
+exported Type in the Python Core. On Python 3.7 ZipImporter *might*
+be reimplemented in Pure Python instead of C.
+
+.. c:var:: PyTypeObject PyZipImporter_Type
+
+   This instance of :c:type:`PyTypeObject` represents the Python zipimporter type;
+   it is the same object as :class:`zipimport.zipimporter` in the Python layer.
+
+   .. note::
+
+      This type used to be named ZipImporter_Type and not exported. Since then it
+      caused problems with subtyping it in another type forcing them to copy most
+      of the implementation from zipimport.c to their extension module which can
+      not be a reasonable thing. So this change was needed.
+
+
+Type check macros
+^^^^^^^^^^^^^^^^^
+
+.. c:function:: int PyZipImporter_Check(PyObject *o)
+
+   Return true if the object *o* is a zipimporter type or an instance of a
+   subtype of the zipimporter type.
diff --git a/Include/Python.h b/Include/Python.h
@@ -120,6 +120,7 @@
 #include "osmodule.h"
 #include "intrcheck.h"
 #include "import.h"
+#include "zipimport.h"
 
 #include "abstract.h"
 #include "bltinmodule.h"

diff --git a/Include/zipimport.h b/Include/zipimport.h
@@ -0,0 +1,14 @@
+#ifndef Py_ZIPIMPORT_H
+#define Py_ZIPIMPORT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+PyAPI_DATA(PyTypeObject) PyZipImporter_Type;
+
+#define ZipImporter_Check(op) PyObject_TypeCheck(op, &PyZipImporter_Type)
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_ZIPIMPORT_H */
diff --git a/Misc/NEWS.d/next/C API/2017-11-20-03-05-40.bpo-32075.U-tgAS.rst b/Misc/NEWS.d/next/C API/2017-11-20-03-05-40.bpo-32075.U-tgAS.rst
@@ -0,0 +1,3 @@
+Exposes ZipImporter Type Object in the include header files. This now fixes
+the issue where nobody can subclass the ZipImporter type in the C API like
+they can on Pure Python.
diff --git a/Modules/clinic/zipimport.c.h b/Modules/clinic/zipimport.c.h
@@ -32,7 +32,7 @@ zipimport_zipimporter___init__(PyObject *self, PyObject *args, PyObject *kwargs)
     int return_value = -1;
     PyObject *path;
 
-    if ((Py_TYPE(self) == &ZipImporter_Type) &&
+    if ((Py_TYPE(self) == &PyZipImporter_Type) &&
         !_PyArg_NoKeywords("zipimporter", kwargs)) {
         goto exit;
     }
@@ -291,4 +291,4 @@ zipimport_zipimporter_get_source(ZipImporter *self, PyObject *arg)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=bac6c9144950eaec input=a9049054013a1b77]*/
+/*[clinic end generated code: output=8ade5cceba9be63d input=a9049054013a1b77]*/
diff --git a/Modules/zipimport.c b/Modules/zipimport.c
@@ -34,8 +34,6 @@ static struct st_zip_searchorder zip_searchorder[] = {
 
 /* zipimporter object definition and support */
 
-typedef struct _zipimporter ZipImporter;
-
 struct _zipimporter {
     PyObject_HEAD
     PyObject *archive;  /* pathname of the Zip archive,
@@ -45,6 +43,8 @@ struct _zipimporter {
     PyObject *files;    /* dict with file info {path: toc_entry} */
 };
 
+typedef struct _zipimporter ZipImporter;
+
 static PyObject *ZipImportError;
 /* read_directory() cache */
 static PyObject *zip_directory_cache = NULL;
@@ -55,15 +55,11 @@ static PyObject *get_data(PyObject *archive, PyObject *toc_entry);
 static PyObject *get_module_code(ZipImporter *self, PyObject *fullname,
                                  int *p_ispackage, PyObject **p_modpath);
 
-static PyTypeObject ZipImporter_Type;
-
-#define ZipImporter_Check(op) PyObject_TypeCheck(op, &ZipImporter_Type)
-
 /*[clinic input]
 module zipimport
-class zipimport.zipimporter "ZipImporter *" "&ZipImporter_Type"
+class zipimport.zipimporter "ZipImporter *" "&PyZipImporter_Type"
 [clinic start generated code]*/
-/*[clinic end generated code: output=da39a3ee5e6b4b0d input=9db8b61557d911e7]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=618e0df7e36f8749]*/
 #include "clinic/zipimport.c.h"
 
 
@@ -805,7 +801,7 @@ static PyMemberDef zipimporter_members[] = {
 
 #define DEFERRED_ADDRESS(ADDR) 0
 
-static PyTypeObject ZipImporter_Type = {
+PyTypeObject PyZipImporter_Type = {
     PyVarObject_HEAD_INIT(DEFERRED_ADDRESS(&PyType_Type), 0)
     "zipimport.zipimporter",
     sizeof(ZipImporter),
@@ -1587,7 +1583,7 @@ PyInit_zipimport(void)
 {
     PyObject *mod;
 
-    if (PyType_Ready(&ZipImporter_Type) < 0)
+    if (PyType_Ready(&PyZipImporter_Type) < 0)
         return NULL;
 
     /* Correct directory separator */
@@ -1608,9 +1604,9 @@ PyInit_zipimport(void)
                            ZipImportError) < 0)
         return NULL;
 
-    Py_INCREF(&ZipImporter_Type);
+    Py_INCREF(&PyZipImporter_Type);
     if (PyModule_AddObject(mod, "zipimporter",
-                           (PyObject *)&ZipImporter_Type) < 0)
+                           (PyObject *)&PyZipImporter_Type) < 0)
         return NULL;
 
     zip_directory_cache = PyDict_New();