>From 9a8851975400ae3d5c2fed6c80c8346565ed390b Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Tue, 5 Nov 2024 21:12:08 +0100
Subject: [PATCH 21/23] wmemcmp tests: Verify N3322 functionality.

* tests/test-wmemcmp.c (main): Add zero-size tests.
---
 ChangeLog            |  5 +++++
 tests/test-wmemcmp.c | 14 ++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 0efaf7854b..6945b84e9e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2024-11-05  Bruno Haible  <bruno@clisp.org>
+
+	wmemcmp tests: Verify N3322 functionality.
+	* tests/test-wmemcmp.c (main): Add zero-size tests.
+
 2024-11-05  Bruno Haible  <bruno@clisp.org>
 
 	wcsncmp tests: Verify N3322 functionality.
diff --git a/tests/test-wmemcmp.c b/tests/test-wmemcmp.c
index 692fcb5e07..d7992b59ce 100644
--- a/tests/test-wmemcmp.c
+++ b/tests/test-wmemcmp.c
@@ -91,5 +91,19 @@ main (int argc, char *argv[])
     ASSERT (wmemcmp (input2, input1, 1) > 0);
   }
 
+  int volatile value;
+
+  /* Test zero-length operations on NULL pointers, allowed by
+     <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3322.pdf>.  */
+
+  value = (wmemcmp (NULL, L"x", 0) == 0);
+  ASSERT (value);
+
+  value = (wmemcmp (L"x", NULL, 0) == 0);
+  ASSERT (value);
+
+  value = (wmemcmp (NULL, NULL, 0) == 0);
+  ASSERT (value);
+
   return test_exit_status;
 }
-- 
2.34.1