Allow plugins to specify pipeline source icons
Reinterpret the PipelineIcon
XML hint: From now on, when no port
attribute is given, the hinted icon will be used for the pipeline source (producer) itself, not for its ports. As before, when the port index is given, the icon will be used for the specified output port.
This change of interpretation does not affect the behaviour of sources and filters with just one output port.
Edited by Jakub Benda