allowSpecialNumbers is broken in some cases

[svuorela]

Parsing a simple [Infinity] works fine, but a more complex { "inf": Infinity } fails

void TestParser::testReadSpecialNumbers() {
    QFETCH(QByteArray, json);
    Parser parser;
    parser.allowSpecialNumbers(true);

    bool ok= false;

    parser.parse(json, &ok);

    QVERIFY(ok);

}

void TestParser::testReadSpecialNumbers_data() {
    QTest::addColumn<QByteArray>("json");

    QTest::newRow("Infinity") << QByteArray("{ \"inf\": Infinity }");
    QTest::newRow("-Infinity") << QByteArray("{ \"inf\": -Infinity }");
    QTest::newRow("NaN") << QByteArray("{ \"nan\": NaN }");
}

This btw worked with a year old QJson.

It is the handling of <ALLOW_SPECIAL_NUMBERS>{ in json_scanner.yy that is somehow broken. Removing the condition in the yy file kind of gives a local fix, but it allows special numbers everywhere.