Do not simply allocate std::vector<> space but also initialize
elements. The data is later accessed as C-pointer array: &var[0].
With most compilers simply reserving space in the vector is
sufficient in order to later access the elements directly.
However actually placing objects in the vector before referencing
them is more correct.
If a plugin implements Vst::IComponent::set_state() but
does not implement Vst::IEditController::setComponentState()
nor dedicated get/setState interface for the IEditController,
querying the parameters using Vst::IEditController::getParamNormalized()
returns values that do reflect the restored state.
In this case the host needs to save/restore all control-parameters,
and ignore values reported by ::getParamNormalized().
This fixes a state save/restore issue with softube.vst3, however
vstpresets are still broken: the GUI (IComponent) is updated,
however the controller isn't.
This also reverts 768d8362cd since it causes crashes
with various plugins (eg. surge.vst3).
Ardour now provides AudioBusBuffers for all audio I/O busses,
regardless of Ardour using those busses.
This fixes crashes of plugins that ignore ProcessData::numInputs
or ProcessData::numOutputs. Those plugins are expected to check
numChannels and channelBuffers for those excess channels, which are
0, NULL for unused busses.
ProcessData numInputs, numOutputs does correctly reflect actual
busses that are in-use (at most one main and one aux for each direction).
This should fix an issue with yabridge and MCompressor.
The plugin has two kMain inputs and expects ProcessData:inputs
to always have two entries, even if the second bus is explicitly
disabled.
see https://hastebin.com/ekewojiqep.txt
```
IComponent::activateBus(type = 0, dir = 0, index = 1, state = false)
data.numInputs = 1;
```
TODO: optimize (pre-allocate) if it works as expected
While Ardour uses separate indices when naming tracks and busses
("track 1", "track 2", "bus 1", "bus 2"), the indices are contiguous
(0: "track 1", 1: "track 2", 2: "bus 1", 3: "bus 2").
