Commit dd98e848 authored by Markus Armbruster's avatar Markus Armbruster
Browse files

qjson: Have qobject_from_json() & friends reject empty and blank 



The last case where qobject_from_json() & friends return null without
setting an error is empty or blank input.  Callers:

* block.c's parse_json_protocol() reports "Could not parse the JSON
  options".  It's marked as a work-around, because it also covered
  actual bugs, but they got fixed in the previous few commits.

* qobject_input_visitor_new_str() reports "JSON parse error".  Also
  marked as work-around.  The recent fixes have made this unreachable,
  because it currently gets called only for input starting with '{'.

* check-qjson.c's empty_input() and blank_input() demonstrate the
  behavior.

* The other callers are not affected since they only pass input with
  exactly one JSON value or, in the case of negative tests, one error.

Fail with "Expecting a JSON value" instead of returning null, and
simplify callers.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-48-armbru@redhat.com>
parent 5d50113c

block.c

+0 −5
Original line number Diff line number Diff line
@@ -1478,11 +1478,6 @@ static QDict *parse_json_filename(const char *filename, Error **errp) 


    options_obj = qobject_from_json(filename, errp);

    if (!options_obj) {

        /* Work around qobject_from_json() lossage TODO fix that */

        if (errp && !*errp) {

            error_setg(errp, "Could not parse the JSON options");

            return NULL;

        }

        error_prepend(errp, "Could not parse the JSON options: ");

        return NULL;

    }

qapi/qobject-input-visitor.c

+0 −5
Original line number Diff line number Diff line
@@ -725,11 +725,6 @@ Visitor *qobject_input_visitor_new_str(const char *str, 
    if (is_json) {

        obj = qobject_from_json(str, errp);

        if (!obj) {

            /* Work around qobject_from_json() lossage TODO fix that */

            if (errp && !*errp) {

                error_setg(errp, "JSON parse error");

                return NULL;

            }

            return NULL;

        }

        args = qobject_to(QDict, obj);

qobject/qjson.c

+4 −0
Original line number Diff line number Diff line
@@ -70,6 +70,10 @@ static QObject *qobject_from_jsonv(const char *string, va_list *ap, 
    json_message_parser_flush(&state.parser);

    json_message_parser_destroy(&state.parser);



    if (!state.result && !state.err) {

        error_setg(&state.err, "Expecting a JSON value");

    }



    error_propagate(errp, state.err);

    return state.result;

}

tests/check-qjson.c

+10 −2
Original line number Diff line number Diff line
@@ -1291,13 +1291,21 @@ static void simple_interpolation(void) 


static void empty_input(void)

{

    QObject *obj = qobject_from_json("", &error_abort);

    Error *err = NULL;

    QObject *obj;



    obj = qobject_from_json("", &err);

    error_free_or_abort(&err);

    g_assert(obj == NULL);

}



static void blank_input(void)

{

    QObject *obj = qobject_from_json("\n ", &error_abort);

    Error *err = NULL;

    QObject *obj;



    obj = qobject_from_json("\n ", &err);

    error_free_or_abort(&err);

    g_assert(obj == NULL);

}