In case a kcfg with arg="true" was used and singleton the static
instance method only accepted a QString config name. This made it
impossible to combine a singleton config with an already existing and
open KSharedConfig::Ptr.
With this change an overloaded instance method is added which takes a
KSharedConfig::Ptr as argument. The private ctor, though, only takes a
KSharedConfig::Ptr and the instance method taking a QString argument
uses KSharedConfig::openConfig on the config file name.
The change is source-incompatible in the following situation:
- kcfgfile arg="true"
- Singleton = true
- Inherits is specified
In this situation the previous revision created an instance method with
a QString argument and passed that to the parent constructor. This is
not in accordance with the documentation. Any user of this behavior was
relying on a bug. With this change now the call to the parent
constructor carries a KSharedConfigPtr.