log* tests: More tests.

[gnulib.git] / m4 / hypot.m4

diff --git a/m4/hypot.m4 b/m4/hypot.m4
index 1837a01..52df05f 100644 (file)
--- a/m4/hypot.m4
+++ b/m4/hypot.m4
@@ -1,4 +1,4 @@
-# hypot.m4 serial 2
+# hypot.m4 serial 3
 dnl Copyright (C) 2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -9,6 +9,9 @@ AC_DEFUN([gl_FUNC_HYPOT],
   m4_divert_text([DEFAULTS], [gl_hypot_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
 
+  dnl Persuade glibc <math.h> to declare hypot().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Determine HYPOT_LIBM.
   gl_COMMON_DOUBLE_MATHFUNC([hypot])