Clear internal call error in 'L' format. Fixes #723201.
Backported to 2.4.
diff --git a/Python/getargs.c b/Python/getargs.c
index 48f9dc4..0684e38 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -610,6 +610,7 @@
 		PY_LONG_LONG *p = va_arg( *p_va, PY_LONG_LONG * );
 		PY_LONG_LONG ival = PyLong_AsLongLong( arg );
 		if( ival == (PY_LONG_LONG)-1 && PyErr_Occurred() ) {
+			PyErr_Clear();
 			return converterr("long<L>", arg, msgbuf, bufsize);
 		} else {
 			*p = ival;