tests cleanup

[Eric Blake]

I noticed some compiler warnings in the m4 testsuite, which were easy to avoid 
even though they didn't affect correctness.

>From a0dc688369a937a657cdf8d35f362c3068b0af9a Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Mon, 15 Sep 2008 14:31:03 -0600
Subject: [PATCH] tests: avoid some compiler warnings

* tests/test-memchr.c (main): Pass NULL indirectly.
* tests/test-closein.c (main): Avoid unused variable.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog            |   12 +++++++++---
 tests/test-closein.c |    7 +++----
 tests/test-memchr.c  |    4 +++-
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 65b21fd..eae0145 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-09-15  Eric Blake  <address@hidden>
+
+       tests: avoid some compiler warnings
+       * tests/test-memchr.c (main): Pass NULL indirectly.
+       * tests/test-closein.c (main): Avoid unused variable.
+
 2008-09-15  Bruno Haible  <address@hidden>
 
        * m4/errno_h.m4 (gl_HEADER_ERRNO_H_BODY): Test for all the macros that
diff --git a/tests/test-closein.c b/tests/test-closein.c
index cf7b30a..57d968b 100644
--- a/tests/test-closein.c
+++ b/tests/test-closein.c
@@ -1,5 +1,5 @@
 /* Test of closein module.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007, 2008 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -36,8 +36,7 @@ int
 main (int argc, char **argv)
 {
   char buf[7];
-  int i = -1;
-  atexit(close_stdin);
+  atexit (close_stdin);
   program_name = argv[0];
 
   /* close_stdin currently relies on ftell, but mingw ftell is
@@ -48,6 +47,6 @@ main (int argc, char **argv)
     close (0);
 
   if (argc > 1)
-    i = fread (buf, 1, 6, stdin);
+    fread (buf, 1, 6, stdin);
   return 0;
 }
diff --git a/tests/test-memchr.c b/tests/test-memchr.c
index d108f1a..ebf3cfc 100644
--- a/tests/test-memchr.c
+++ b/tests/test-memchr.c
@@ -41,6 +41,8 @@
 int
 main ()
 {
+  void *nil = NULL; /* Use to avoid gcc attribute((nonnull)) warnings.  */
+
   size_t n = 0x100000;
   char *input = malloc (n);
   ASSERT (input);
@@ -56,7 +58,7 @@ main ()
   ASSERT (MEMCHR (input, 'a', n) == input);
 
   ASSERT (MEMCHR (input, 'a', 0) == NULL);
-  ASSERT (MEMCHR (NULL, 'a', 0) == NULL);
+  ASSERT (MEMCHR (nil, 'a', 0) == NULL);
 
   ASSERT (MEMCHR (input, 'b', n) == input + 1);
   ASSERT (MEMCHR (input, 'c', n) == input + 2);
-- 
1.6.0