- add check for pointer equality prior to performing the O(n) pass

- while here change 's' to 's1' in strcoll

Submitted by:	eadler@
Reviewed by:	theraven@
Approved by:	brooks@
MFC after:	2 weeks

4 files changed, 28 insertions, 18 deletions

diff --git a/lib/libc/string/strcasecmp.c b/lib/libc/string/strcasecmp.c
index 65e042e..dae91d3 100644
--- a/lib/libc/string/strcasecmp.c
+++ b/lib/libc/string/strcasecmp.c
@@ -48,6 +48,9 @@ strcasecmp_l(const char *s1, const char *s2, locale_t locale)
 	const u_char
 			*us1 = (const u_char *)s1,
 			*us2 = (const u_char *)s2;
+	if (s1 == s2)
+	    return (0);
+
 	FIX_LOCALE(locale);
 
 	while (tolower_l(*us1, locale) == tolower_l(*us2++, locale))
@@ -65,18 +68,21 @@ int
 strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t locale)
 {
 	FIX_LOCALE(locale);
-	if (n != 0) {
-		const u_char
-				*us1 = (const u_char *)s1,
-				*us2 = (const u_char *)s2;
 
-		do {
-			if (tolower_l(*us1, locale) != tolower_l(*us2++, locale))
-				return (tolower_l(*us1, locale) - tolower_l(*--us2, locale));
-			if (*us1++ == '\0')
-				break;
-		} while (--n != 0);
-	}
+	const u_char
+			*us1 = (const u_char *)s1,
+			*us2 = (const u_char *)s2;
+	
+	if (( s1 == s2) | (n == 0))
+	    return (0);
+
+
+	do {
+		if (tolower_l(*us1, locale) != tolower_l(*us2++, locale))
+			return (tolower_l(*us1, locale) - tolower_l(*--us2, locale));
+		if (*us1++ == '\0')
+			break;
+	} while (--n != 0);
 	return (0);
 }
 
diff --git a/lib/libc/string/strcmp.c b/lib/libc/string/strcmp.c
index 95c778d..70fd22d 100644
--- a/lib/libc/string/strcmp.c
+++ b/lib/libc/string/strcmp.c
@@ -44,6 +44,9 @@ __FBSDID("$FreeBSD$");
 int
 strcmp(const char *s1, const char *s2)
 {
+	if (s1 == s2)
+	    return (0);
+
 	while (*s1 == *s2++)
 		if (*s1++ == '\0')
 			return (0);
diff --git a/lib/libc/string/strcoll.c b/lib/libc/string/strcoll.c
index a918fca..8add885 100644
--- a/lib/libc/string/strcoll.c
+++ b/lib/libc/string/strcoll.c
@@ -40,7 +40,7 @@ __FBSDID("$FreeBSD$");
 #include <stdio.h>
 
 int
-strcoll_l(const char *s, const char *s2, locale_t locale)
+strcoll_l(const char *s1, const char *s2, locale_t locale)
 {
 	int len, len2, prim, prim2, sec, sec2, ret, ret2;
 	const char *t, *t2;
@@ -50,16 +50,16 @@ strcoll_l(const char *s, const char *s2, locale_t locale)
 		(struct xlocale_collate*)locale->components[XLC_COLLATE];
 
 	if (table->__collate_load_error)
-		return strcmp(s, s2);
+		return strcmp(s1, s2);
 
 	len = len2 = 1;
 	ret = ret2 = 0;
 	if (table->__collate_substitute_nontrivial) {
-		t = tt = __collate_substitute(table, s);
+		t = tt = __collate_substitute(table, s1);
 		t2 = tt2 = __collate_substitute(table, s2);
 	} else {
 		tt = tt2 = NULL;
-		t = s;
+		t = s1;
 		t2 = s2;
 	}
 	while(*t && *t2) {
@@ -95,8 +95,8 @@ strcoll_l(const char *s, const char *s2, locale_t locale)
 }
 
 int
-strcoll(const char *s, const char *s2)
+strcoll(const char *s1, const char *s2)
 {
-	return strcoll_l(s, s2, __get_locale());
+	return strcoll_l(s1, s2, __get_locale());
 }
 
diff --git a/lib/libc/string/strncmp.c b/lib/libc/string/strncmp.c
index 5bc3d5e..46db3f9 100644
--- a/lib/libc/string/strncmp.c
+++ b/lib/libc/string/strncmp.c
@@ -39,8 +39,9 @@ int
 strncmp(const char *s1, const char *s2, size_t n)
 {
 
-	if (n == 0)
+	if ((n == 0) | (s1 == s2))
 		return (0);
+
 	do {
 		if (*s1 != *s2++)
 			return (*(const unsigned char *)s1 -