830dfdda24
Adding a MIDI only plugin at a point where there is no MIDI data, and/or additional audio signals results in an 'Impossible' match. Those are usually resolved by trying to replicate the plugin, and the fallback is to "Replicate 1 time". While this is effectively equivalent with ExactMatch (use 1 instance), it is semantically different: Audio sources will be ignored and if there is no MIDI signal, the MIDI input remains unconnected. It is the opposite to "Hide" (plugin has more inputs of a given type, which can be fed by silence), since it has fewer inputs of a given type signals are "dropped". Strictly speaking we should special case this "Replicate 1 time" case to "Drop" [sic]. which only assert(!reconfigurable_io()).
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