gh-77782: Py_FdIsInteractive() now uses PyConfig.interactive (#93916)

Doc/c-api/sys.rst

@@ -21,10 +21,12 @@ Operating System Utilities
 
    Return true (nonzero) if the standard I/O file *fp* with name *filename* is
    deemed interactive.  This is the case for files for which ``isatty(fileno(fp))``
-   is true.  If the global flag :c:data:`Py_InteractiveFlag` is true, this function
+   is true.  If the :c:member:`PyConfig.interactive` is non-zero, this function
    also returns true if the *filename* pointer is ``NULL`` or if the name is equal to
    one of the strings ``'<stdin>'`` or ``'???'``.
 
+   This function must not be called before Python is initialized.
+
 
 .. c:function:: void PyOS_BeforeFork()
 

Lib/test/test_capi.py

@@ -70,16 +70,17 @@ class CAPITest(unittest.TestCase):
                                   'import _testcapi;'
                                   '_testcapi.crash_no_current_thread()'],
                                  stdout=subprocess.PIPE,
-                                 stderr=subprocess.PIPE)
+                                 stderr=subprocess.PIPE,
+                                 text=True)
         (out, err) = p.communicate()
-        self.assertEqual(out, b'')
+        self.assertEqual(out, '')
         # This used to cause an infinite loop.
-        self.assertTrue(err.rstrip().startswith(
-                         b'Fatal Python error: '
-                         b'PyThreadState_Get: '
-                         b'the function must be called with the GIL held, '
-                         b'but the GIL is released '
-                         b'(the current Python thread state is NULL)'),
+        msg = ("Fatal Python error: PyThreadState_Get: "
+               "the function must be called with the GIL held, "
+               "after Python initialization and before Python finalization, "
+               "but the GIL is released "
+               "(the current Python thread state is NULL)")
+        self.assertTrue(err.rstrip().startswith(msg),
                         err)
 
     def test_memoryview_from_NULL_pointer(self):

Python/ceval.c

@@ -347,9 +347,9 @@ void _Py_NO_RETURN
 _Py_FatalError_TstateNULL(const char *func)
 {
     _Py_FatalErrorFunc(func,
-                       "the function must be called with the GIL held, "
-                       "but the GIL is released "
-                       "(the current Python thread state is NULL)");
+        "the function must be called with the GIL held, "
+        "after Python initialization and before Python finalization, "
+        "but the GIL is released (the current Python thread state is NULL)");
 }
 
 int

Python/initconfig.c

@@ -180,7 +180,7 @@ int Py_UTF8Mode = 0;
 int Py_DebugFlag = 0; /* Needed by parser.c */
 int Py_VerboseFlag = 0; /* Needed by import.c */
 int Py_QuietFlag = 0; /* Needed by sysmodule.c */
-int Py_InteractiveFlag = 0; /* Needed by Py_FdIsInteractive() below */
+int Py_InteractiveFlag = 0; /* Previously, was used by Py_FdIsInteractive() */
 int Py_InspectFlag = 0; /* Needed to determine whether to exit at SystemExit */
 int Py_OptimizeFlag = 0; /* Needed by compile.c */
 int Py_NoSiteFlag = 0; /* Suppress 'import site' */

Python/pylifecycle.c

@@ -2938,28 +2938,30 @@ Py_Exit(int sts)
 int
 Py_FdIsInteractive(FILE *fp, const char *filename)
 {
-    if (isatty((int)fileno(fp)))
+    if (isatty(fileno(fp))) {
         return 1;
-    if (!Py_InteractiveFlag)
+    }
+    if (!_Py_GetConfig()->interactive) {
         return 0;
-    return (filename == NULL) ||
-           (strcmp(filename, "<stdin>") == 0) ||
-           (strcmp(filename, "???") == 0);
+    }
+    return ((filename == NULL)
+            || (strcmp(filename, "<stdin>") == 0)
+            || (strcmp(filename, "???") == 0));
 }
 
 
 int
 _Py_FdIsInteractive(FILE *fp, PyObject *filename)
 {
-    if (isatty((int)fileno(fp))) {
+    if (isatty(fileno(fp))) {
         return 1;
     }
-    if (!Py_InteractiveFlag) {
+    if (!_Py_GetConfig()->interactive) {
         return 0;
     }
-    return (filename == NULL) ||
-           (PyUnicode_CompareWithASCIIString(filename, "<stdin>") == 0) ||
-           (PyUnicode_CompareWithASCIIString(filename, "???") == 0);
+    return ((filename == NULL)
+            || (PyUnicode_CompareWithASCIIString(filename, "<stdin>") == 0)
+            || (PyUnicode_CompareWithASCIIString(filename, "???") == 0));
 }
 
 

Python/pystate.c

@@ -2136,6 +2136,7 @@ _Py_GetConfig(void)
 {
     assert(PyGILState_Check());
     PyThreadState *tstate = _PyThreadState_GET();
+    _Py_EnsureTstateNotNULL(tstate);
     return _PyInterpreterState_GetConfig(tstate->interp);
 }