general improvements

diff --git a/compat/memmem.c b/compat/memmem.c
index cd0d8773641f2fdc808d8b246a8dd2bcd0e5814d..56bcb4277f47c295993c853a84edfe45e6aa3911 100644 (file)
--- a/compat/memmem.c
+++ b/compat/memmem.c
@@ -5,6 +5,8 @@ void *gitmemmem(const void *haystack, size_t haystack_len,
 {
        const char *begin = haystack;
        const char *last_possible = begin + haystack_len - needle_len;
+       const char *tail = needle;
+       char point;
 
        /*
         * The first occurrence of the empty string is deemed to occur at
@@ -20,8 +22,9 @@ void *gitmemmem(const void *haystack, size_t haystack_len,
        if (haystack_len < needle_len)
                return NULL;
 
+       point = *tail++;
        for (; begin <= last_possible; begin++) {
-               if (!memcmp(begin, needle, needle_len))
+               if (*begin == point && !memcmp(begin + 1, tail, needle_len - 1))
                        return (void *)begin;
        }