python
diff --git a/‎Misc/NEWS.d/next/Core and Builtins/2023-04-26-16-26-35.gh-issue-103907.kiONZQ.rst‎
Lines changed: 2 additions & 0 deletions b/‎Misc/NEWS.d/next/Core and Builtins/2023-04-26-16-26-35.gh-issue-103907.kiONZQ.rst‎
Lines changed: 2 additions & 0 deletions
diff --git a/‎Objects/boolobject.c‎
Lines changed: 1 addition & 7 deletions b/‎Objects/boolobject.c‎
Lines changed: 1 addition & 7 deletions
diff --git a/‎Python/bytecodes.c‎
Lines changed: 14 additions & 32 deletions b/‎Python/bytecodes.c‎
Lines changed: 14 additions & 32 deletions
@@ -0,0 +1,2 @@
+Don't modify the refcounts of known immortal objects (:const:`True`,
+:const:`False`, and :const:`None`) in the main interpreter loop.
@@ -20,13 +20,7 @@ bool_repr(PyObject *self)
 
 PyObject *PyBool_FromLong(long ok)
 {
-    PyObject *result;
-
-    if (ok)
-        result = Py_True;
-    else
-        result = Py_False;
-    return Py_NewRef(result);
+    return ok ? Py_True : Py_False;
 }
 
 /* We define bool_new to always return either Py_True or Py_False */
 
@@ -270,7 +270,6 @@ dummy_func(
             else {
                 res = Py_False;
             }
-            Py_INCREF(res);
         }
 
         inst(UNARY_INVERT, (value -- res)) {
@@ -967,7 +966,7 @@ dummy_func(
             if (PyErr_GivenExceptionMatches(exc_value, PyExc_StopIteration)) {
                 value = Py_NewRef(((PyStopIterationObject *)exc_value)->value);
                 DECREF_INPUTS();
-                none = Py_NewRef(Py_None);
+                none = Py_None;
             }
             else {
                 _PyErr_SetRaisedException(tstate, Py_NewRef(exc_value));
@@ -1452,7 +1451,7 @@ dummy_func(
                 DECREF_INPUTS();
                 ERROR_IF(true, error);
             }
-            Py_DECREF(none_val);
+            assert(Py_IsNone(none_val));
             DECREF_INPUTS();
         }
 
@@ -1993,7 +1992,6 @@ dummy_func(
             _Py_DECREF_SPECIALIZED(left, _PyFloat_ExactDealloc);
             _Py_DECREF_SPECIALIZED(right, _PyFloat_ExactDealloc);
             res = (sign_ish & oparg) ? Py_True : Py_False;
-            Py_INCREF(res);
         }
 
         // Similar to COMPARE_OP_FLOAT
@@ -2012,7 +2010,6 @@ dummy_func(
             _Py_DECREF_SPECIALIZED(left, (destructor)PyObject_Free);
             _Py_DECREF_SPECIALIZED(right, (destructor)PyObject_Free);
             res = (sign_ish & oparg) ? Py_True : Py_False;
-            Py_INCREF(res);
         }
 
         // Similar to COMPARE_OP_FLOAT, but for ==, != only
@@ -2028,20 +2025,19 @@ dummy_func(
             assert((oparg & 0xf) == COMPARISON_NOT_EQUALS || (oparg & 0xf) == COMPARISON_EQUALS);
             assert(COMPARISON_NOT_EQUALS + 1 == COMPARISON_EQUALS);
             res = ((COMPARISON_NOT_EQUALS + eq) & oparg) ? Py_True : Py_False;
-            Py_INCREF(res);
         }
 
         inst(IS_OP, (left, right -- b)) {
             int res = Py_Is(left, right) ^ oparg;
             DECREF_INPUTS();
-            b = Py_NewRef(res ? Py_True : Py_False);
+            b = res ? Py_True : Py_False;
         }
 
         inst(CONTAINS_OP, (left, right -- b)) {
             int res = PySequence_Contains(right, left);
             DECREF_INPUTS();
             ERROR_IF(res < 0, error);
-            b = Py_NewRef((res^oparg) ? Py_True : Py_False);
+            b = (res ^ oparg) ? Py_True : Py_False;
         }
 
         inst(CHECK_EG_MATCH, (exc_value, match_type -- rest, match)) {
@@ -2074,7 +2070,7 @@ dummy_func(
 
             int res = PyErr_GivenExceptionMatches(left, right);
             DECREF_INPUTS();
-            b = Py_NewRef(res ? Py_True : Py_False);
+            b = res ? Py_True : Py_False;
         }
 
          inst(IMPORT_NAME, (level, fromlist -- res)) {
@@ -2101,14 +2097,10 @@ dummy_func(
         }
 
         inst(POP_JUMP_IF_FALSE, (cond -- )) {
-            if (Py_IsTrue(cond)) {
-                _Py_DECREF_NO_DEALLOC(cond);
-            }
-            else if (Py_IsFalse(cond)) {
-                _Py_DECREF_NO_DEALLOC(cond);
+            if (Py_IsFalse(cond)) {
                 JUMPBY(oparg);
             }
-            else {
+            else if (!Py_IsTrue(cond)) {
                 int err = PyObject_IsTrue(cond);
                 DECREF_INPUTS();
                 if (err == 0) {
@@ -2121,14 +2113,10 @@ dummy_func(
         }
 
         inst(POP_JUMP_IF_TRUE, (cond -- )) {
-            if (Py_IsFalse(cond)) {
-                _Py_DECREF_NO_DEALLOC(cond);
-            }
-            else if (Py_IsTrue(cond)) {
-                _Py_DECREF_NO_DEALLOC(cond);
+            if (Py_IsTrue(cond)) {
                 JUMPBY(oparg);
             }
-            else {
+            else if (!Py_IsFalse(cond)) {
                 int err = PyObject_IsTrue(cond);
                 DECREF_INPUTS();
                 if (err > 0) {
@@ -2145,14 +2133,10 @@ dummy_func(
                 DECREF_INPUTS();
                 JUMPBY(oparg);
             }
-            else {
-                _Py_DECREF_NO_DEALLOC(value);
-            }
         }
 
         inst(POP_JUMP_IF_NONE, (value -- )) {
             if (Py_IsNone(value)) {
-                _Py_DECREF_NO_DEALLOC(value);
                 JUMPBY(oparg);
             }
             else {
@@ -2188,19 +2172,19 @@ dummy_func(
             }
             else {
                 ERROR_IF(_PyErr_Occurred(tstate), error);  // Error!
-                attrs = Py_NewRef(Py_None);  // Failure!
+                attrs = Py_None;  // Failure!
             }
         }
 
         inst(MATCH_MAPPING, (subject -- subject, res)) {
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_MAPPING;
-            res = Py_NewRef(match ? Py_True : Py_False);
+            res = match ? Py_True : Py_False;
             PREDICT(POP_JUMP_IF_FALSE);
         }
 
         inst(MATCH_SEQUENCE, (subject -- subject, res)) {
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_SEQUENCE;
-            res = Py_NewRef(match ? Py_True : Py_False);
+            res = match ? Py_True : Py_False;
             PREDICT(POP_JUMP_IF_FALSE);
         }
 
@@ -2392,7 +2376,7 @@ dummy_func(
             STAT_INC(FOR_ITER, hit);
             _PyInterpreterFrame *gen_frame = (_PyInterpreterFrame *)gen->gi_iframe;
             frame->return_offset = oparg;
-            _PyFrame_StackPush(gen_frame, Py_NewRef(Py_None));
+            _PyFrame_StackPush(gen_frame, Py_None);
             gen->gi_frame_state = FRAME_EXECUTING;
             gen->gi_exc_state.previous_item = tstate->exc_info;
             tstate->exc_info = &gen->gi_exc_state;
@@ -2499,7 +2483,7 @@ dummy_func(
                 prev_exc = exc_info->exc_value;
             }
             else {
-                prev_exc = Py_NewRef(Py_None);
+                prev_exc = Py_None;
             }
             assert(PyExceptionInstance_Check(new_exc));
             exc_info->exc_value = Py_NewRef(new_exc);
@@ -3393,7 +3377,6 @@ dummy_func(
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
             if (Py_IsNone(value)) {
-                _Py_DECREF_NO_DEALLOC(value);
                 offset = oparg;
             }
             else {
@@ -3408,7 +3391,6 @@ dummy_func(
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
             if (Py_IsNone(value)) {
-                _Py_DECREF_NO_DEALLOC(value);
                 offset = 0;
             }
             else {
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Don't modify the refcounts of known immortal objects (:const:`True`,
	`2`	+:const:`False`, and :const:`None`) in the main interpreter loop.
Original file line number	Diff line number	Diff line change
`@@ -20,13 +20,7 @@ bool_repr(PyObject *self)`
`20`	`20`
`21`	`21`	`PyObject *PyBool_FromLong(long ok)`
`22`	`22`	`{`
`23`		`- PyObject *result;`
`24`		`-`
`25`		`- if (ok)`
`26`		`- result = Py_True;`
`27`		`- else`
`28`		`- result = Py_False;`
`29`		`- return Py_NewRef(result);`
	`23`	`+ return ok ? Py_True : Py_False;`
`30`	`24`	`}`
`31`	`25`
`32`	`26`	`/* We define bool_new to always return either Py_True or Py_False */`