Provisionally include strlcmp(), although it is not (currently) used

anywhere.  Opinion is divided as to whether this is useful, or whether
its usefulness is outweighed by its awkwardness.  Still, we have it, so
we may as well commit it.

lib/core/cryb_strlcmp.c

@@ -33,12 +33,16 @@
 
 #include <cryb/strlcmp.h>
 
-/* like strcmp, but only compares up to len characters */
+/*
+ * Like strncmp, but also asserts that s1[len] == '\0'.  Useful in parsers
+ * to verify that the next len characters of the input (s2) match a
+ * specific keyword (s1).
+ */
 int
 cryb_strlcmp(const char *s1, const char *s2, size_t len)
 {
 
-	for (; len && *s1 && *s2; --len, ++s1, ++s2)
+	for (; len && *s2; --len, ++s1, ++s2)
 		if (*s1 != *s2)
 			return ((unsigned char)*s1 - (unsigned char)*s2);
 	return ((unsigned char)*s1);

t/Makefile.am

@@ -37,7 +37,7 @@ endif
 TESTS =
 
 # libcryb-core
-TESTS += t_ctype t_strlcat t_strlcpy
+TESTS += t_ctype t_strlcat t_strlcmp t_strlcpy
 TESTS += t_string t_wstring
 EXTRA_DIST += t__string.c
 

t/t_strlcmp.c

@@ -0,0 +1,150 @@
+/*-
+ * Copyright (c) 2014 Dag-Erling Smørgrav
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "cryb/impl.h"
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#undef HAVE_STRLCMP
+#include <cryb/strlcmp.h>
+
+#include "t.h"
+
+#define T_MAGIC_STR	"squeamish ossifrage"
+#define T_MAGIC_INITIAL	's'
+#define T_MAGIC_LEN	(sizeof(T_MAGIC_STR) - 1)
+#define T_BUFSIZE	(T_MAGIC_LEN + 1 + T_MAGIC_LEN + 1)
+
+struct t_case {
+	const char *desc;
+	const char *pfx;
+	const char *str;
+	size_t len;
+	int res;
+};
+
+/***************************************************************************
+ * Test cases
+ */
+static struct t_case t_cases[] = {
+	{
+		.desc	= "empty, empty",
+		.pfx	= "",
+		.str	= "",
+		.len	= 0,
+		.res	= 0,
+	},
+	{
+		.desc	= "empty, short",
+		.pfx	= "",
+		.str	= T_MAGIC_STR,
+		.len	= 0,
+		.res	= 0,
+	},
+	{
+		.desc	= "short, empty",
+		.pfx	= T_MAGIC_STR,
+		.str	= "",
+		.len	= T_MAGIC_LEN,
+		.res	= T_MAGIC_INITIAL,
+	},
+	{
+		.desc	= "short, short",
+		.pfx	= T_MAGIC_STR,
+		.str	= T_MAGIC_STR,
+		.len	= T_MAGIC_LEN,
+		.res	= 0,
+	},
+	{
+		.desc	= "short, long",
+		.pfx	= T_MAGIC_STR,
+		.str	= T_MAGIC_STR " " T_MAGIC_STR,
+		.len	= T_MAGIC_LEN,
+		.res	= 0,
+	},
+	{
+		.desc	= "long, short",
+		.pfx	= T_MAGIC_STR " " T_MAGIC_STR,
+		.str	= T_MAGIC_STR,
+		.len	= T_MAGIC_LEN + 1 + T_MAGIC_LEN,
+		.res	= ' ',
+	},
+	{
+		.desc	= "mismatch",
+		.pfx	= "sin",
+		.str	= "sunny",
+		.len	= 3,
+		.res	= 'i' - 'u',
+	},
+	{
+		.desc	= "too short",
+		.pfx	= "sun",
+		.str	= "sunny",
+		.len	= 5,
+		.res	= '\0' - 'n',
+	},
+};
+
+/***************************************************************************
+ * Test function
+ */
+static int
+t_strlcmp(char **desc CRYB_UNUSED, void *arg)
+{
+	struct t_case *t = arg;
+	int res;
+
+	res = strlcmp(t->pfx, t->str, t->len);
+	return (t_compare_x8(t->res, res));
+}
+
+
+/***************************************************************************
+ * Boilerplate
+ */
+
+int
+t_prepare(int argc, char *argv[])
+{
+	int i, n;
+
+	(void)argc;
+	(void)argv;
+	n = sizeof t_cases / sizeof t_cases[0];
+	for (i = 0; i < n; ++i)
+		t_add_test(t_strlcmp, &t_cases[i], t_cases[i].desc);
+	return (0);
+}
+
+void
+t_cleanup(void)
+{
+}