strstr: replace GPLv2-only implementation from Linux by LGPLv2.1 from uclibc

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27393 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 23 insertions, 22 deletions

diff --git a/firmware/libc/strstr.c b/firmware/libc/strstr.c
index 73fab1cc63..ea1fe9eded 100644
--- a/firmware/libc/strstr.c
+++ b/firmware/libc/strstr.c
@@ -5,34 +5,35 @@
  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
  *                     \/            \/     \/    \/            \/
- * $Id: $
  *
- * Copyright (C) 1991, 1992  Linus Torvalds
- * (from linux/lib/string.c)
+ * Copyright (C) 2002     Manuel Novoa III
+ * Copyright (C) 2000-2005 Erik Andersen <andersen@uclibc.org>
+ *
+ * Licensed under the LGPL v2.1, code originally in uclibc
  *
  ****************************************************************************/
-
 #include <string.h>
 
-/**
- * strstr - Find the first substring in a %NUL terminated string
- * @s1: The string to be searched
- * @s2: The string to search for
- */
+/* NOTE: This is the simple-minded O(len(s1) * len(s2)) worst-case approach. */
+
 char *strstr(const char *s1, const char *s2)
 {
-    int l1, l2;
+        register const char *s = s1;
+        register const char *p = s2;
 
-    l2 = strlen(s2);
-    if (!l2)
-        return (char *)s1;
-    l1 = strlen(s1);
-    while (l1 >= l2) {
-        l1--;
-        if (!memcmp(s1, s2, l2))
-            return (char *)s1;
-        s1++;
-    }
-    return NULL;
+        do {
+                if (!*p) {
+                        return (char *) s1;;
+                }
+                if (*p == *s) {
+                        ++p;
+                        ++s;
+                } else {
+                        p = s2;
+                        if (!*s) {
+                                return NULL;
+                        }
+                        s = ++s1;
+                }
+        } while (1);
 }
-