Issue #10538. Put a reference to the source object in the Py_buffer when
converting the old buffer for PyArgs_ParseTuple with *s
diff --git a/Python/getargs.c b/Python/getargs.c
index eccdc9b..a6cebbc 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -1410,7 +1410,7 @@
         *errmsg = "convertible to a buffer";
         return count;
     }
-    PyBuffer_FillInfo(view, NULL, buf, count, 1, 0);
+    PyBuffer_FillInfo(view, arg, buf, count, 1, 0);
     return 0;
 }