opt: define NULL

Headers should stand alone; we use NULL, so we should make sure it's defined.

diff --git a/ccan/opt/opt.h b/ccan/opt/opt.h
index 5757778577e2079b31641f176dd6976fe11c4d3d..812fec869aeba311d27e0dd4844ab34d862a9958 100644 (file)
--- a/ccan/opt/opt.h
+++ b/ccan/opt/opt.h
@@ -3,6 +3,7 @@
 #include <ccan/compiler/compiler.h>
 #include <ccan/typesafe_cb/typesafe_cb.h>
 #include <stdbool.h>
+#include <stdlib.h>
 
 struct opt_table;