Use _POSIX_C_SOURCE in gzguts.h, instead of _POSIX_SOURCE.

madler · madler · commit 1382e661143e · 2024-02-06T18:27:24.000-08:00
diff --git a/gzguts.h b/gzguts.h
@@ -25,8 +25,8 @@
 #  include <limits.h>
 #endif
 
-#ifndef _POSIX_SOURCE
-#  define _POSIX_SOURCE
+#ifndef _POSIX_C_SOURCE
+#  define _POSIX_C_SOURCE 200112L
 #endif
 #include <fcntl.h>
 
