Issue #24436: Added const qualifiers for char* arguments of _PyTraceback_Add.

Patch by Michael Ensslin.

Include/traceback.h

@@ -24,7 +24,7 @@ PyAPI_FUNC(int) PyTraceBack_Here(struct _frame *);
 PyAPI_FUNC(int) PyTraceBack_Print(PyObject *, PyObject *);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _Py_DisplaySourceLine(PyObject *, PyObject *, int, int);
-PyAPI_FUNC(void) _PyTraceback_Add(char *, char *, int);
+PyAPI_FUNC(void) _PyTraceback_Add(const char *, const char *, int);
 #endif
 
 /* Reveal traceback type so we can typecheck traceback objects */

Python/traceback.c

@@ -143,7 +143,7 @@ PyTraceBack_Here(PyFrameObject *frame)
 }
 
 /* Insert a frame into the traceback for (funcname, filename, lineno). */
-void _PyTraceback_Add(char *funcname, char *filename, int lineno)
+void _PyTraceback_Add(const char *funcname, const char *filename, int lineno)
 {
     PyObject *globals = NULL;
     PyCodeObject *code = NULL;