+/*
+ * If we have va_copy(), use it for assigning va_list's.
+ */
+#if defined(HAVE___VA_COPY)
+#define begin_va_copy(dst,src) __va_copy(dst, src)
+#define end_va_copy(dst) va_end(dst)
+#elif defined(va_copy) || defined(HAVE_VA_COPY)
+#define begin_va_copy(dst,src) va_copy(dst, src)
+#define end_va_copy(dst) va_end(dst)
+#else
+#define begin_va_copy(dst,src) (dst) = (src)
+#define end_va_copy(dst) /* nothing */
+#endif
+