1 files changed, 17 insertions, 0 deletions
diff --git a/gl/m4/isblank.m4 b/gl/m4/isblank.m4
new file mode 100644
index 0000000..5e1b783
--- /dev/null
+++ b/gl/m4/isblank.m4
@@ -0,0 +1,17 @@
+# isblank.m4 serial 3
+dnl Copyright (C) 2009-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_ISBLANK],
+[
+  dnl Persuade glibc <ctype.h> to declare isblank().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  AC_REQUIRE([gl_CTYPE_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([isblank])
+  if test $ac_cv_func_isblank = no; then
+    HAVE_ISBLANK=0
+  fi
+])