1 files changed, 53 insertions, 0 deletions
diff --git a/m4/strchrnul.m4 b/m4/strchrnul.m4
new file mode 100644
index 0000000..9b9ab11
--- /dev/null
+++ b/m4/strchrnul.m4
@@ -0,0 +1,53 @@
+# strchrnul.m4 serial 12
+dnl Copyright (C) 2003, 2007, 2009-2023 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_STRCHRNUL],
+[
+  dnl Persuade glibc <string.h> to declare strchrnul().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  AC_REQUIRE([gl_STRING_H_DEFAULTS])
+  gl_CHECK_FUNCS_ANDROID([strchrnul], [[#include <string.h>]])
+  if test $ac_cv_func_strchrnul = no; then
+    HAVE_STRCHRNUL=0
+    case "$gl_cv_onwards_func_strchrnul" in
+      future*) REPLACE_STRCHRNUL=1 ;;
+    esac
+  else
+    AC_CACHE_CHECK([whether strchrnul works],
+      [gl_cv_func_strchrnul_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
+#include <string.h> /* for strchrnul */
+]], [[const char *buf = "a";
+      return strchrnul (buf, 'b') != buf + 1;
+    ]])],
+        [gl_cv_func_strchrnul_works=yes],
+        [gl_cv_func_strchrnul_works=no],
+        [dnl Cygwin 1.7.9 introduced strchrnul, but it was broken until 1.7.10
+         AC_EGREP_CPP([Lucky user],
+           [
+#if defined __CYGWIN__
+ #include <cygwin/version.h>
+ #if CYGWIN_VERSION_DLL_COMBINED > CYGWIN_VERSION_DLL_MAKE_COMBINED (1007, 9)
+  Lucky user
+ #endif
+#else
+  Lucky user
+#endif
+           ],
+           [gl_cv_func_strchrnul_works="guessing yes"],
+           [gl_cv_func_strchrnul_works="guessing no"])
+        ])
+      ])
+    case "$gl_cv_func_strchrnul_works" in
+      *yes) ;;
+      *) REPLACE_STRCHRNUL=1 ;;
+    esac
+  fi
+])
+
+# Prerequisites of lib/strchrnul.c.
+AC_DEFUN([gl_PREREQ_STRCHRNUL], [:])