receive-pack: use find_commit_header() in check_cert_push_options()

Use the public function find_commit_header() instead of find_header() to
simplify the code.  This is possible and safe because we're operating on
a strbuf, which is always NUL-terminated, so there is no risk of running
over the end of the buffer.  It cannot contain NUL within the buffer, as
it is built using strbuf_addstr(), only.

The string comparison becomes more complicated because we need to check
for NUL explicitly after comparing the length-limited option, but on the
flip side we don't need to clean up allocations or track the remaining
buffer length.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index e36b1d619f5c075fc26617fb26972dc21d561e75..8ebb3a872f1ca65135bed5b85e177ef25ac1a22e 100644 (file)
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -718,35 +718,29 @@ leave:
 static int check_cert_push_options(const struct string_list *push_options)
 {
        const char *buf = push_cert.buf;
-       int len = push_cert.len;
 
-       char *option;
-       const char *next_line;
+       const char *option;
+       size_t optionlen;
        int options_seen = 0;
 
        int retval = 1;
 
-       if (!len)
+       if (!*buf)
                return 1;
 
-       while ((option = find_header(buf, len, "push-option", &next_line))) {
-               len -= (next_line - buf);
-               buf = next_line;
+       while ((option = find_commit_header(buf, "push-option", &optionlen))) {
+               buf = option + optionlen + 1;
                options_seen++;
                if (options_seen > push_options->nr
-                   || strcmp(option,
-                             push_options->items[options_seen - 1].string)) {
-                       retval = 0;
-                       goto leave;
-               }
-               free(option);
+                   || strncmp(push_options->items[options_seen - 1].string,
+                              option, optionlen)
+                   || push_options->items[options_seen - 1].string[optionlen])
+                       return 0;
        }
 
        if (options_seen != push_options->nr)
                retval = 0;
 
-leave:
-       free(option);
        return retval;
 }