pathspec: allow escaped query values

In our own .gitattributes file we have attributes such as:

    *.[ch] whitespace=indent,trail,space

When querying for attributes we want to be able to ask for the exact
value, i.e.

    git ls-files :(attr:whitespace=indent,trail,space)

should work, but the commas are used in the attr magic to introduce
the next attr, such that this query currently fails with

fatal: Invalid pathspec magic 'trail' in ':(attr:whitespace=indent,trail,space)'

This change allows escaping characters by a backslash, such that the query

    git ls-files :(attr:whitespace=indent\,trail\,space)

will match all path that have the value "indent,trail,space" for the
whitespace attribute. To accomplish this, we need to modify two places.
First `parse_long_magic` needs to not stop early upon seeing a comma or
closing paren that is escaped. As a second step we need to remove any
escaping from the attr value.

Based on a patch by Stefan Beller <sbeller@google.com>

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Brandon Williams 2017-03-13 11:23:22 -07:00 committed by Junio C Hamano
parent b0db704652
commit c5af19f9ab
2 changed files with 67 additions and 4 deletions

View File

@ -89,6 +89,51 @@ static void prefix_magic(struct strbuf *sb, int prefixlen, unsigned magic)
strbuf_addf(sb, ",prefix:%d)", prefixlen);
}
static size_t strcspn_escaped(const char *s, const char *stop)
{
const char *i;
for (i = s; *i; i++) {
/* skip the escaped character */
if (i[0] == '\\' && i[1]) {
i++;
continue;
}
if (strchr(stop, *i))
break;
}
return i - s;
}
static inline int invalid_value_char(const char ch)
{
if (isalnum(ch) || strchr(",-_", ch))
return 0;
return -1;
}
static char *attr_value_unescape(const char *value)
{
const char *src;
char *dst, *ret;
ret = xmallocz(strlen(value));
for (src = value, dst = ret; *src; src++, dst++) {
if (*src == '\\') {
if (!src[1])
die(_("Escape character '\\' not allowed as "
"last character in attr value"));
src++;
}
if (invalid_value_char(*src))
die("cannot use '%c' for value matching", *src);
*dst = *src;
}
*dst = '\0';
return ret;
}
static void parse_pathspec_attr_match(struct pathspec_item *item, const char *value)
{
struct string_list_item *si;
@ -131,10 +176,9 @@ static void parse_pathspec_attr_match(struct pathspec_item *item, const char *va
if (attr[attr_len] != '=')
am->match_mode = MATCH_SET;
else {
const char *v = &attr[attr_len + 1];
am->match_mode = MATCH_VALUE;
am->value = xstrdup(&attr[attr_len + 1]);
if (strchr(am->value, '\\'))
die(_("attr spec values must not contain backslashes"));
am->value = attr_value_unescape(v);
}
break;
}
@ -239,7 +283,7 @@ static const char *parse_long_magic(unsigned *magic, int *prefix_len,
const char *nextat;
for (pos = elem + 2; *pos && *pos != ')'; pos = nextat) {
size_t len = strcspn(pos, ",)");
size_t len = strcspn_escaped(pos, ",)");
int i;
if (pos[len] == ',')

View File

@ -178,4 +178,23 @@ test_expect_success 'abort on asking for wrong magic' '
test_must_fail git ls-files . ":(attr:!label=foo)"
'
test_expect_success 'check attribute list' '
cat <<-EOF >>.gitattributes &&
* whitespace=indent,trail,space
EOF
git ls-files ":(attr:whitespace=indent\,trail\,space)" >actual &&
git ls-files >expect &&
test_cmp expect actual
'
test_expect_success 'backslash cannot be the last character' '
test_must_fail git ls-files ":(attr:label=foo\\ labelA=bar)" 2>actual &&
test_i18ngrep "not allowed as last character in attr value" actual
'
test_expect_success 'backslash cannot be used as a value' '
test_must_fail git ls-files ":(attr:label=f\\\oo)" 2>actual &&
test_i18ngrep "for value matching" actual
'
test_done