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author | Junio C Hamano <gitster@pobox.com> | 2023-02-27 10:08:57 -0800 |
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committer | Junio C Hamano <gitster@pobox.com> | 2023-02-27 10:08:57 -0800 |
commit | dda83e69d08ce37c64157007e050a142660fd15c (patch) | |
tree | 1b432741919859123c726059befb4d674d459c58 /refs.c | |
parent | 7dc55a04d8da6f430ee9a0c07d68c6098a9dea15 (diff) | |
parent | 613bef56b820cf7f24dc4b3ae65fc91826368185 (diff) | |
download | git-dda83e69d08ce37c64157007e050a142660fd15c.tar.gz |
Merge branch 'jk/shorten-unambiguous-ref-wo-sscanf'
sscanf(3) used in "git symbolic-ref --short" implementation found
to be not working reliably on macOS in UTF-8 locales. Rewrite the
code to avoid sscanf() altogether to work it around.
* jk/shorten-unambiguous-ref-wo-sscanf:
shorten_unambiguous_ref(): avoid sscanf()
shorten_unambiguous_ref(): use NUM_REV_PARSE_RULES constant
shorten_unambiguous_ref(): avoid integer truncation
Diffstat (limited to 'refs.c')
-rw-r--r-- | refs.c | 93 |
1 files changed, 48 insertions, 45 deletions
@@ -1310,65 +1310,68 @@ int update_ref(const char *msg, const char *refname, old_oid, flags, onerr); } +/* + * Check that the string refname matches a rule of the form + * "{prefix}%.*s{suffix}". So "foo/bar/baz" would match the rule + * "foo/%.*s/baz", and return the string "bar". + */ +static const char *match_parse_rule(const char *refname, const char *rule, + size_t *len) +{ + /* + * Check that rule matches refname up to the first percent in the rule. + * We can bail immediately if not, but otherwise we leave "rule" at the + * %-placeholder, and "refname" at the start of the potential matched + * name. + */ + while (*rule != '%') { + if (!*rule) + BUG("rev-parse rule did not have percent"); + if (*refname++ != *rule++) + return NULL; + } + + /* + * Check that our "%" is the expected placeholder. This assumes there + * are no other percents (placeholder or quoted) in the string, but + * that is sufficient for our rev-parse rules. + */ + if (!skip_prefix(rule, "%.*s", &rule)) + return NULL; + + /* + * And now check that our suffix (if any) matches. + */ + if (!strip_suffix(refname, rule, len)) + return NULL; + + return refname; /* len set by strip_suffix() */ +} + char *refs_shorten_unambiguous_ref(struct ref_store *refs, const char *refname, int strict) { int i; - static char **scanf_fmts; - static int nr_rules; - char *short_name; struct strbuf resolved_buf = STRBUF_INIT; - if (!nr_rules) { - /* - * Pre-generate scanf formats from ref_rev_parse_rules[]. - * Generate a format suitable for scanf from a - * ref_rev_parse_rules rule by interpolating "%s" at the - * location of the "%.*s". - */ - size_t total_len = 0; - size_t offset = 0; - - /* the rule list is NULL terminated, count them first */ - for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++) - /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */ - total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1; - - scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len)); - - offset = 0; - for (i = 0; i < nr_rules; i++) { - assert(offset < total_len); - scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset; - offset += xsnprintf(scanf_fmts[i], total_len - offset, - ref_rev_parse_rules[i], 2, "%s") + 1; - } - } - - /* bail out if there are no rules */ - if (!nr_rules) - return xstrdup(refname); - - /* buffer for scanf result, at most refname must fit */ - short_name = xstrdup(refname); - /* skip first rule, it will always match */ - for (i = nr_rules - 1; i > 0 ; --i) { + for (i = NUM_REV_PARSE_RULES - 1; i > 0 ; --i) { int j; int rules_to_fail = i; - int short_name_len; + const char *short_name; + size_t short_name_len; - if (1 != sscanf(refname, scanf_fmts[i], short_name)) + short_name = match_parse_rule(refname, ref_rev_parse_rules[i], + &short_name_len); + if (!short_name) continue; - short_name_len = strlen(short_name); - /* * in strict mode, all (except the matched one) rules * must fail to resolve to a valid non-ambiguous ref */ if (strict) - rules_to_fail = nr_rules; + rules_to_fail = NUM_REV_PARSE_RULES; /* * check if the short name resolves to a valid ref, @@ -1388,7 +1391,8 @@ char *refs_shorten_unambiguous_ref(struct ref_store *refs, */ strbuf_reset(&resolved_buf); strbuf_addf(&resolved_buf, rule, - short_name_len, short_name); + cast_size_t_to_int(short_name_len), + short_name); if (refs_ref_exists(refs, resolved_buf.buf)) break; } @@ -1399,12 +1403,11 @@ char *refs_shorten_unambiguous_ref(struct ref_store *refs, */ if (j == rules_to_fail) { strbuf_release(&resolved_buf); - return short_name; + return xmemdupz(short_name, short_name_len); } } strbuf_release(&resolved_buf); - free(short_name); return xstrdup(refname); } |