gh-111089: Revert PyUnicode_AsUTF8() changes (#111833)

* Revert "gh-111089: Use PyUnicode_AsUTF8() in Argument Clinic (#111585)"

This reverts commit d9b606b3d04fc56fb0bcc479d7d6c14562edb5e2.

* Revert "gh-111089: Use PyUnicode_AsUTF8() in getargs.c (#111620)"

This reverts commit cde1071b2a72e8261ca66053ef61431b7f3a81fd.

* Revert "gh-111089: PyUnicode_AsUTF8() now raises on embedded NUL (#111091)"

This reverts commit d731579bfb9a497cfb0076cb6b221058a20088fe.

* Revert "gh-111089: Add PyUnicode_AsUTF8() to the limited C API (#111121)"

This reverts commit d8f32be5b6a736dc2fc9dca3f1bf176c82fc9b44.

* Revert "gh-111089: Use PyUnicode_AsUTF8() in sqlite3 (#111122)"

This reverts commit 37e4e20eaa8f27ada926d49e5971fecf0477ad26.

3 files changed, 16 insertions, 6 deletions

diff --git a/Modules/_multiprocessing/clinic/multiprocessing.c.h b/Modules/_multiprocessing/clinic/multiprocessing.c.h
index 9133d5d..6d4f5c2 100644
--- a/Modules/_multiprocessing/clinic/multiprocessing.c.h
+++ b/Modules/_multiprocessing/clinic/multiprocessing.c.h
@@ -138,10 +138,15 @@ _multiprocessing_sem_unlink(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("sem_unlink", "argument", "str", arg);
         goto exit;
     }
-    name = PyUnicode_AsUTF8(arg);
+    Py_ssize_t name_length;
+    name = PyUnicode_AsUTF8AndSize(arg, &name_length);
     if (name == NULL) {
         goto exit;
     }
+    if (strlen(name) != (size_t)name_length) {
+        PyErr_SetString(PyExc_ValueError, "embedded null character");
+        goto exit;
+    }
     return_value = _multiprocessing_sem_unlink_impl(module, name);
 
 exit:
@@ -159,4 +164,4 @@ exit:
 #ifndef _MULTIPROCESSING_SEND_METHODDEF
     #define _MULTIPROCESSING_SEND_METHODDEF
 #endif /* !defined(_MULTIPROCESSING_SEND_METHODDEF) */
-/*[clinic end generated code: output=c6735cbc59b6f324 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=73b4cb8428d816da input=a9049054013a1b77]*/
diff --git a/Modules/_multiprocessing/clinic/semaphore.c.h b/Modules/_multiprocessing/clinic/semaphore.c.h
index ae340c2..7c85511 100644
--- a/Modules/_multiprocessing/clinic/semaphore.c.h
+++ b/Modules/_multiprocessing/clinic/semaphore.c.h
@@ -266,10 +266,15 @@ _multiprocessing_SemLock(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         _PyArg_BadArgument("SemLock", "argument 'name'", "str", fastargs[3]);
         goto exit;
     }
-    name = PyUnicode_AsUTF8(fastargs[3]);
+    Py_ssize_t name_length;
+    name = PyUnicode_AsUTF8AndSize(fastargs[3], &name_length);
     if (name == NULL) {
         goto exit;
     }
+    if (strlen(name) != (size_t)name_length) {
+        PyErr_SetString(PyExc_ValueError, "embedded null character");
+        goto exit;
+    }
     unlink = PyObject_IsTrue(fastargs[4]);
     if (unlink < 0) {
         goto exit;
@@ -537,4 +542,4 @@ exit:
 #ifndef _MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF
     #define _MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF
 #endif /* !defined(_MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF) */
-/*[clinic end generated code: output=fd94dc907e6ab57f input=a9049054013a1b77]*/
+/*[clinic end generated code: output=d57992037e6770b6 input=a9049054013a1b77]*/
diff --git a/Modules/_multiprocessing/posixshmem.c b/Modules/_multiprocessing/posixshmem.c
index b1f776c..cd08a9f 100644
--- a/Modules/_multiprocessing/posixshmem.c
+++ b/Modules/_multiprocessing/posixshmem.c
@@ -48,7 +48,7 @@ _posixshmem_shm_open_impl(PyObject *module, PyObject *path, int flags,
 {
     int fd;
     int async_err = 0;
-    const char *name = PyUnicode_AsUTF8(path);
+    const char *name = PyUnicode_AsUTF8AndSize(path, NULL);
     if (name == NULL) {
         return -1;
     }
@@ -87,7 +87,7 @@ _posixshmem_shm_unlink_impl(PyObject *module, PyObject *path)
 {
     int rv;
     int async_err = 0;
-    const char *name = PyUnicode_AsUTF8(path);
+    const char *name = PyUnicode_AsUTF8AndSize(path, NULL);
     if (name == NULL) {
         return NULL;
     }