Return QVariantList when using list as Signal argument

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>

1 files changed, 2 insertions, 0 deletions

diff --git a/sources/pyside2/libpyside/pysidesignal.cpp b/sources/pyside2/libpyside/pysidesignal.cpp
index 367f85fff..aa215aa45 100644
--- a/sources/pyside2/libpyside/pysidesignal.cpp
+++ b/sources/pyside2/libpyside/pysidesignal.cpp
@@ -687,6 +687,8 @@ QByteArray getTypeName(PyObject *type)
             return QByteArrayLiteral("double");
         if (objType == &PyBool_Type)
             return QByteArrayLiteral("bool");
+        if (objType == &PyList_Type)
+            return QByteArrayLiteral("QVariantList");
         if (Py_TYPE(objType) == SbkEnumType_TypeF())
             return Shiboken::Enum::getCppName(objType);
         return QByteArrayLiteral("PyObject");