json: Accept overlong \xC0\x80 as U+0000 ("modified UTF-8")

Since the JSON grammer doesn't accept U+0000 anywhere, this merely
exchanges one kind of parse error for another.  It's purely for
consistency with qobject_to_json(), which accepts \xC0\x80 (see commit
e2ec3f9768).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-26-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2018-08-23 18:39:52 +02:00
parent de930f45cb
commit 4b1c0cd7c7
3 changed files with 3 additions and 9 deletions

View File

@ -93,7 +93,7 @@
* interpolation = %((l|ll|I64)[du]|[ipsf]) * interpolation = %((l|ll|I64)[du]|[ipsf])
* *
* Note: * Note:
* - Input must be encoded in UTF-8. * - Input must be encoded in modified UTF-8.
* - Decoding and validating is left to the parser. * - Decoding and validating is left to the parser.
*/ */

View File

@ -200,7 +200,7 @@ static QString *qstring_from_escaped_str(JSONParserContext *ctxt,
} }
} else { } else {
cp = mod_utf8_codepoint(ptr, 6, &end); cp = mod_utf8_codepoint(ptr, 6, &end);
if (cp <= 0) { if (cp < 0) {
parse_error(ctxt, token, "invalid UTF-8 sequence in string"); parse_error(ctxt, token, "invalid UTF-8 sequence in string");
goto out; goto out;
} }

View File

@ -152,12 +152,6 @@ static void string_with_quotes(void)
static void utf8_string(void) static void utf8_string(void)
{ {
/* /*
* Problem: we can't easily deal with embedded U+0000. Parsing
* the JSON string "this \\u0000" is fun" yields "this \0 is fun",
* which gets misinterpreted as NUL-terminated "this ". We should
* consider using overlong encoding \xC0\x80 for U+0000 ("modified
* UTF-8").
*
* Most test cases are scraped from Markus Kuhn's UTF-8 decoder * Most test cases are scraped from Markus Kuhn's UTF-8 decoder
* capability and stress test at * capability and stress test at
* http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt * http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt
@ -586,7 +580,7 @@ static void utf8_string(void)
{ {
/* \U+0000 */ /* \U+0000 */
"\xC0\x80", "\xC0\x80",
NULL, "\xC0\x80",
"\\u0000", "\\u0000",
}, },
{ {