cuserid: support invocation with a null pointer argument

[musl] / src / math / scalbf.c

diff --git a/src/math/scalbf.c b/src/math/scalbf.c
index 9436497..f44ed5b 100644 (file)
--- a/src/math/scalbf.c
+++ b/src/math/scalbf.c
@@ -13,6 +13,7 @@
  * ====================================================
  */
 
+#define _GNU_SOURCE
 #include <math.h>
 
 float scalbf(float x, float fn)