DIX: Add strncasecmp from FreeBSD, make strcasecmp args const

Add strncasecmp (as we're now using it) in case someone doesn't have it,
and also change strncasecmp args to be const, in accordance with
everything else.

2 files changed, 26 insertions, 2 deletions

diff --git a/dix/strcasecmp.c b/dix/strcasecmp.c
index 58f0961e6..8f7c5c402 100644
--- a/dix/strcasecmp.c
+++ b/dix/strcasecmp.c
@@ -33,7 +33,7 @@
 
 #ifdef NEED_STRCASECMP
 int
-xstrcasecmp(char *str1,char *str2)
+xstrcasecmp(const char *str1, const char *str2)
 {
     const u_char *us1 = (const u_char *)str1, *us2 = (const u_char *)str2;
 
@@ -46,3 +46,22 @@ xstrcasecmp(char *str1,char *str2)
     return (tolower(*us1) - tolower(*us2));
 }
 #endif
+
+#ifdef NEED_STRNCASECMP
+int
+xstrncasecmp(const char *s1, const char *s2, size_t n)
+{
+    if (n != 0) {
+        const u_char *us1 = (const u_char *)s1, *us2 = (const u_char *)s2;
+
+        do {
+            if (tolower(*us1) != tolower(*us2++))
+                return (tolower(*us1) - tolower(*--us2));
+            if (*us1++ == '\0')
+                break;
+        } while (--n != 0);
+    }
+
+    return 0;
+}
+#endif
diff --git a/include/dix.h b/include/dix.h
index 300718dd9..a8c2b3b5a 100644
--- a/include/dix.h
+++ b/include/dix.h
@@ -601,7 +601,12 @@ typedef struct {
 /* strcasecmp.c */
 #if NEED_STRCASECMP
 #define strcasecmp xstrcasecmp
-extern int xstrcasecmp(char *s1, char *s2);
+extern int xstrcasecmp(const char *s1, const char *s2);
+#endif
+
+#if NEED_STRNCASECMP
+#define strncasecmp xstrncasecmp
+extern int xstrncasecmp(const char *s1, const char *s2, size_t n);
 #endif
 
 extern int XItoCoreType(int xi_type);