bpo-37076: _thread.start_new_thread() calls _PyErr_WriteUnraisableMsg() (GH-13617)

_thread.start_new_thread() now logs uncaught exception raised by the
function using sys.unraisablehook(), rather than sys.excepthook(), so
the hook gets access to the function which raised the exception.

1 files changed, 4 insertions, 14 deletions

diff --git a/Modules/_threadmodule.c b/Modules/_threadmodule.c
index 680e8ca..2b1a98f 100644
--- a/Modules/_threadmodule.c
+++ b/Modules/_threadmodule.c
@@ -1002,25 +1002,15 @@ t_bootstrap(void *boot_raw)
     res = PyObject_Call(boot->func, boot->args, boot->keyw);
     if (res == NULL) {
         if (PyErr_ExceptionMatches(PyExc_SystemExit))
+            /* SystemExit is ignored silently */
             PyErr_Clear();
         else {
-            PyObject *file;
-            PyObject *exc, *value, *tb;
-            PySys_WriteStderr(
-                "Unhandled exception in thread started by ");
-            PyErr_Fetch(&exc, &value, &tb);
-            file = _PySys_GetObjectId(&PyId_stderr);
-            if (file != NULL && file != Py_None)
-                PyFile_WriteObject(boot->func, file, 0);
-            else
-                PyObject_Print(boot->func, stderr, 0);
-            PySys_WriteStderr("\n");
-            PyErr_Restore(exc, value, tb);
-            PyErr_PrintEx(0);
+            _PyErr_WriteUnraisableMsg("in thread started by", boot->func);
         }
     }
-    else
+    else {
         Py_DECREF(res);
+    }
     Py_DECREF(boot->func);
     Py_DECREF(boot->args);
     Py_XDECREF(boot->keyw);