bpo-39413: Implement os.unsetenv() on Windows (GH-18163)
The os.unsetenv() function is now also available on Windows.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 6a68752..3a8e6aa 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -10083,6 +10083,64 @@
#ifdef MS_WINDOWS
+static PyObject*
+win32_putenv(PyObject *name, PyObject *value)
+{
+ /* Search from index 1 because on Windows starting '=' is allowed for
+ defining hidden environment variables. */
+ if (PyUnicode_GET_LENGTH(name) == 0 ||
+ PyUnicode_FindChar(name, '=', 1, PyUnicode_GET_LENGTH(name), 1) != -1)
+ {
+ PyErr_SetString(PyExc_ValueError, "illegal environment variable name");
+ return NULL;
+ }
+ PyObject *unicode;
+ if (value != NULL) {
+ unicode = PyUnicode_FromFormat("%U=%U", name, value);
+ }
+ else {
+ unicode = PyUnicode_FromFormat("%U=", name);
+ }
+ if (unicode == NULL) {
+ return NULL;
+ }
+
+ Py_ssize_t size;
+ /* PyUnicode_AsWideCharString() rejects embedded null characters */
+ wchar_t *env = PyUnicode_AsWideCharString(unicode, &size);
+ Py_DECREF(unicode);
+
+ if (env == NULL) {
+ return NULL;
+ }
+ if (size > _MAX_ENV) {
+ PyErr_Format(PyExc_ValueError,
+ "the environment variable is longer than %u characters",
+ _MAX_ENV);
+ PyMem_Free(env);
+ return NULL;
+ }
+
+ /* _wputenv() and SetEnvironmentVariableW() update the environment in the
+ Process Environment Block (PEB). _wputenv() also updates CRT 'environ'
+ and '_wenviron' variables, whereas SetEnvironmentVariableW() does not.
+
+ Prefer _wputenv() to be compatible with C libraries using CRT
+ variables and CRT functions using these variables (ex: getenv()). */
+ int err = _wputenv(env);
+ PyMem_Free(env);
+
+ if (err) {
+ posix_error();
+ return NULL;
+ }
+
+ Py_RETURN_NONE;
+}
+#endif
+
+
+#ifdef MS_WINDOWS
/*[clinic input]
os.putenv
@@ -10097,47 +10155,7 @@
os_putenv_impl(PyObject *module, PyObject *name, PyObject *value)
/*[clinic end generated code: output=d29a567d6b2327d2 input=ba586581c2e6105f]*/
{
- const wchar_t *env;
- Py_ssize_t size;
-
- /* Search from index 1 because on Windows starting '=' is allowed for
- defining hidden environment variables. */
- if (PyUnicode_GET_LENGTH(name) == 0 ||
- PyUnicode_FindChar(name, '=', 1, PyUnicode_GET_LENGTH(name), 1) != -1)
- {
- PyErr_SetString(PyExc_ValueError, "illegal environment variable name");
- return NULL;
- }
- PyObject *unicode = PyUnicode_FromFormat("%U=%U", name, value);
- if (unicode == NULL) {
- return NULL;
- }
-
- env = PyUnicode_AsUnicodeAndSize(unicode, &size);
- if (env == NULL)
- goto error;
- if (size > _MAX_ENV) {
- PyErr_Format(PyExc_ValueError,
- "the environment variable is longer than %u characters",
- _MAX_ENV);
- goto error;
- }
- if (wcslen(env) != (size_t)size) {
- PyErr_SetString(PyExc_ValueError, "embedded null character");
- goto error;
- }
-
- if (_wputenv(env)) {
- posix_error();
- goto error;
- }
- Py_DECREF(unicode);
-
- Py_RETURN_NONE;
-
-error:
- Py_DECREF(unicode);
- return NULL;
+ return win32_putenv(name, value);
}
/* repeat !defined(MS_WINDOWS) to workaround an Argument Clinic issue */
#elif (defined(HAVE_SETENV) || defined(HAVE_PUTENV)) && !defined(MS_WINDOWS)
@@ -10186,7 +10204,23 @@
#endif /* defined(HAVE_SETENV) || defined(HAVE_PUTENV) */
-#ifdef HAVE_UNSETENV
+#ifdef MS_WINDOWS
+/*[clinic input]
+os.unsetenv
+ name: unicode
+ /
+
+Delete an environment variable.
+[clinic start generated code]*/
+
+static PyObject *
+os_unsetenv_impl(PyObject *module, PyObject *name)
+/*[clinic end generated code: output=54c4137ab1834f02 input=4d6a1747cc526d2f]*/
+{
+ return win32_putenv(name, NULL);
+}
+/* repeat !defined(MS_WINDOWS) to workaround an Argument Clinic issue */
+#elif defined(HAVE_UNSETENV) && !defined(MS_WINDOWS)
/*[clinic input]
os.unsetenv
name: FSConverter
@@ -10199,16 +10233,13 @@
os_unsetenv_impl(PyObject *module, PyObject *name)
/*[clinic end generated code: output=54c4137ab1834f02 input=2bb5288a599c7107]*/
{
-#ifndef HAVE_BROKEN_UNSETENV
- int err;
-#endif
-
#ifdef HAVE_BROKEN_UNSETENV
unsetenv(PyBytes_AS_STRING(name));
#else
- err = unsetenv(PyBytes_AS_STRING(name));
- if (err)
+ int err = unsetenv(PyBytes_AS_STRING(name));
+ if (err) {
return posix_error();
+ }
#endif
#ifdef PY_PUTENV_DICT