Avoid using a second sentinel.

Author: ZeroIntensity

Python/pystate.c

@@ -3473,9 +3473,6 @@ PyInterpreterView_FromMain(void)
 static const PyThreadStateToken *_no_tstate_sentinel = (const PyThreadStateToken *)&_no_tstate_sentinel;
 #define NO_TSTATE_SENTINEL ((PyThreadStateToken *)_no_tstate_sentinel)
 
-static const PyThreadStateToken *_detached_sentinel = (const PyThreadStateToken *)&_detached_sentinel;
-#define DETACHED_TSTATE_SENTINEL ((PyThreadStateToken *)_detached_sentinel)
-
 PyThreadStateToken *
 PyThreadState_Ensure(PyInterpreterGuard *guard)
 {
@@ -3495,7 +3492,7 @@ PyThreadState_Ensure(PyInterpreterGuard *guard)
         assert(attached_tstate == NULL);
         ++detached_gilstate->ensure.counter;
         _PyThreadState_Attach(detached_gilstate);
-        return DETACHED_TSTATE_SENTINEL;
+        return NO_TSTATE_SENTINEL;
     }
 
     PyThreadState *fresh_tstate = _PyThreadState_NewBound(interp,
@@ -3557,14 +3554,14 @@ PyThreadState_Release(PyThreadStateToken *token)
     if (remaining != 0) {
         // If the corresponding PyThreadState_Ensure() call used a detached
         // thread state, we want to detach it again.
-        if (token == DETACHED_TSTATE_SENTINEL) {
+        if (token == NO_TSTATE_SENTINEL) {
             PyThreadState_Swap(NULL);
         }
         return;
     }
 
     PyThreadState *to_restore;
-    if (token == NO_TSTATE_SENTINEL || token == DETACHED_TSTATE_SENTINEL) {
+    if (token == NO_TSTATE_SENTINEL) {
         to_restore = NULL;
     }
     else {

Tools/c-analyzer/cpython/ignored.tsv

@@ -786,4 +786,3 @@ Objects/dictobject.c	-	PyFrozenDict_Type	-
 ## False positives
 Python/specialize.c	-	_Py_InitCleanup	-
 Python/pystate.c	-	_no_tstate_sentinel	-
-Python/pystate.c	-	_detached_sentinel	-