@matheusbsbs / matheus-bagliano / commits / fe6eb7f2c5

commit: provide a function to find a header in a buffer

Usually when we parse a commit, we read it line by line and handle each individual line (e.g., parse_commit and parse_commit_header). Sometimes, however, we only care about extracting a single header. Code in this situation is stuck doing an ad-hoc parse of the commit buffer. Let's provide a reusable function to locate a header within the commit. The code is modeled after pretty.c's get_header, which is used to extract the encoding. Since some callers may not have the "struct commit" to go along with the buffer, we drop that parameter. The only thing lost is a warning for truncated commits, but that's OK. This shouldn't happen in practice, and even if it does, there's no particular reason that this function needs to complain about it. It either finds the header it was asked for, or it doesn't (and in the latter case, the caller will typically complain). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Aug 27, 2014 at 03:56 UTC fe6eb7f2c506190c817407accf27834005a57f2b

3 files changed +39 -27

commit.c

+22

@@ -1660,3 +1660,25 @@ void print_commit_list(struct commit_list *list,

1660 printf(format, sha1_to_hex(list->item->object.sha1));

1661 }

1662 }

1663 +

1664 +const char *find_commit_header(const char *msg, const char *key, size_t *out_len)

1665 +{

1666 + int key_len = strlen(key);

1667 + const char *line = msg;

1668 +

1669 + while (line) {

1670 + const char *eol = strchrnul(line, '\n');

1671 +

1672 + if (line == eol)

1673 + return NULL;

1674 +

1675 + if (eol - line > key_len &&

1676 + !strncmp(line, key, key_len) &&

1677 + line[key_len] == ' ') {

1678 + *out_len = eol - line - key_len - 1;

1679 + return line + key_len + 1;

1680 + }

1681 + line = *eol ? eol + 1 : NULL;

1682 + }

1683 + return NULL;

1684 +}

commit.h

+11

@@ -313,6 +313,17 @@ extern struct commit_extra_header *read_commit_extra_headers(struct commit *, co

313

314 extern void free_commit_extra_headers(struct commit_extra_header *extra);

315

316 +/*

317 + * Search the commit object contents given by "msg" for the header "key".

318 + * Returns a pointer to the start of the header contents, or NULL. The length

319 + * of the header, up to the first newline, is returned via out_len.

320 + *

321 + * Note that some headers (like mergetag) may be multi-line. It is the caller's

322 + * responsibility to parse further in this case!

323 + */

324 +extern const char *find_commit_header(const char *msg, const char *key,

325 + size_t *out_len);

326 +

327 typedef void (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,

328 void *cb_data);

329

pretty.c

+6 -27

@@ -547,31 +547,11 @@ static void add_merge_info(const struct pretty_print_context *pp,

547 strbuf_addch(sb, '\n');

548 }

549

550 -static char *get_header(const struct commit *commit, const char *msg,

551 - const char *key)

550 +static char *get_header(const char *msg, const char *key)

551 {

553 - int key_len = strlen(key);

554 - const char *line = msg;

555 -

556 - while (line) {

557 - const char *eol = strchrnul(line, '\n'), *next;

558 -

559 - if (line == eol)

560 - return NULL;

561 - if (!*eol) {

562 - warning("malformed commit (header is missing newline): %s",

563 - sha1_to_hex(commit->object.sha1));

564 - next = NULL;

565 - } else

566 - next = eol + 1;

567 - if (eol - line > key_len &&

568 - !strncmp(line, key, key_len) &&

569 - line[key_len] == ' ') {

570 - return xmemdupz(line + key_len + 1, eol - line - key_len - 1);

571 - }

572 - line = next;

573 - }

574 - return NULL;

552 + size_t len;

553 + const char *v = find_commit_header(msg, key, &len);

554 + return v ? xmemdupz(v, len) : NULL;

555 }

556

557 static char *replace_encoding_header(char *buf, const char *encoding)

@@ -617,11 +597,10 @@ const char *logmsg_reencode(const struct commit *commit,

597

598 if (!output_encoding || !*output_encoding) {

599 if (commit_encoding)

620 - *commit_encoding =

621 - get_header(commit, msg, "encoding");

600 + *commit_encoding = get_header(msg, "encoding");

601 return msg;

602 }

624 - encoding = get_header(commit, msg, "encoding");

603 + encoding = get_header(msg, "encoding");

604 if (commit_encoding)

605 *commit_encoding = encoding;

606 use_encoding = encoding ? encoding : utf8;