rebase -r: let `label` generate safer labels

The `label` todo command in interactive rebases creates temporary refs in the `refs/rewritten/` namespace. These refs are stored as loose refs, i.e. as files in `.git/refs/rewritten/`, therefore they have to conform with file name limitations on the current filesystem in addition to the accepted ref format. This poses a problem in particular on NTFS/FAT, where e.g. the colon, double-quote and pipe characters are disallowed as part of a file name. Let's safeguard against this by replacing not only white-space characters by dashes, but all non-alpha-numeric ones. However, we exempt non-ASCII UTF-8 characters from that, as it should be quite possible to reflect branch names such as `↯↯↯` in refs/file names. Signed-off-by: Matthew Rogers <mattr94@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Matthew Rogers committed Nov 17, 2019 at 23:16 UTC cd5522271f6b985114b33332e148bff2283b0440

2 files changed +25 -1

sequencer.c

+19 -1

@@ -4471,8 +4471,26 @@ static const char *label_oid(struct object_id *oid, const char *label,

4471 } else {

4472 struct strbuf *buf = &state->buf;

4473

4474 + /*

4475 + * Sanitize labels by replacing non-alpha-numeric characters

4476 + * (including white-space ones) by dashes, as they might be

4477 + * illegal in file names (and hence in ref names).

4478 + *

4479 + * Note that we retain non-ASCII UTF-8 characters (identified

4480 + * via the most significant bit). They should be all acceptable

4481 + * in file names. We do not validate the UTF-8 here, that's not

4482 + * the job of this function.

4483 + */

4484 for (; *label; label++)

4475 - strbuf_addch(buf, isspace(*label) ? '-' : *label);

4485 + if ((*label & 0x80) || isalnum(*label))

4486 + strbuf_addch(buf, *label);

4487 + /* avoid leading dash and double-dashes */

4488 + else if (buf->len && buf->buf[buf->len - 1] != '-')

4489 + strbuf_addch(buf, '-');

4490 + if (!buf->len) {

4491 + strbuf_addstr(buf, "rev-");

4492 + strbuf_add_unique_abbrev(buf, oid, default_abbrev);

4493 + }

4494 label = buf->buf;

4495

4496 if ((buf->len == the_hash_algo->hexsz &&

t/t3430-rebase-merges.sh

@@ -468,4 +468,10 @@ test_expect_success '--rebase-merges with strategies' '

468 test_cmp expect G.t

469 '

470

471 +test_expect_success '--rebase-merges with commit that can generate bad characters for filename' '

472 + git checkout -b colon-in-label E &&

473 + git merge -m "colon: this should work" G &&

474 + git rebase --rebase-merges --force-rebase E

475 +'

476 +

477 test_done