When determinating the type name for Signal types, we have special treatment for a couple of Python types like str, int, float, bool, etc, if the current type is none of those, we return a generic 'PyObject', which in most cases works, but not for specific interaction with WebChannel. Emiting one of the previous types works out of the box, but when using: ... = Signal(list) we get a message stating: > js: Uncaught TypeError: Cannot read property '0' of null meaning that list was not really passed correctly. The solution for this is to use: ... = Signal('QVariantList') but as a string, not type. Passing a string means that we will return the same type as string from the getTypeName function, so this patch adds a condition to treat Signal(list) as a Signal('QVariantList'). We were using this workaround for some bugs related to QtWebKit, so it was accepted as solution. Fixes: PYSIDE-981 Change-Id: I06720ca62426d51decc2ab08d380f7f967460788 Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io> Reviewed-by: Christian Tismer <tismer@stackless.com>