lupdate truncates namespace

QString foo::tr(const char* msg) 
{ 
    return QCoreApplication::translate("foo", msg); 
}
//...
void bar()
{
    foo:tr("String");
}

<context>
    <name>f</name>
    <message>
        <location filename="file.cpp" line="1"/>
        <source>String</source>
        <translation>String</translation>
    </message>
</context>