From a66a47e168804aa0a62a3a5810d7f8dd9b647dab Mon Sep 17 00:00:00 2001 From: Liu Aleaxander Date: Sat, 9 Oct 2010 23:10:14 +0800 Subject: [PATCH] lib: Update memmem function The current memem implementation can not handle the case that the length of the third parameter(needle) is equal *ONE*. So that the current strstr implemention doesn't work when the lenght of substring is ONE. For example, strstr("linux", "l") it will return NULL instead of "linux", which is not right. This code is stolen from klibc ;) Signed-off-by: Liu Aleaxander --- com32/lib/memmem.c | 45 +++++++++++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/com32/lib/memmem.c b/com32/lib/memmem.c index 8558a80..7c42f1c 100644 --- a/com32/lib/memmem.c +++ b/com32/lib/memmem.c @@ -18,26 +18,35 @@ void *memmem(const void *haystack, size_t n, const void *needle, size_t m) size_t j, k, l; - if (m > n) - return NULL; + if (m > n || !m || !n) + return NULL; - if (x[0] == x[1]) { - k = 2; - l = 1; - } else { - k = 1; - l = 2; - } + if (1 != m) { + if (x[0] == x[1]) { + k = 2; + l = 1; + } else { + k = 1; + l = 2; + } - j = 0; - while (j <= n - m) { - if (x[1] != y[j + 1]) { - j += k; - } else { - if (!memcmp(x + 2, y + j + 2, m - 2) && x[0] == y[j]) - return (void *)&y[j]; - j += l; - } + j = 0; + while (j <= n - m) { + if (x[1] != y[j + 1]) { + j += k; + } else { + if (!memcmp(x + 2, y + j + 2, m - 2) + && x[0] == y[j]) + return (void *)&y[j]; + j += l; + } + } + } else { + do { + if (*y == *x) + return (void *)y; + y++; + } while (--n); } return NULL; -- 2.7.4