Mod Matrix bug - hopefully squashed

[DanH]

One for @Christoph-Hart . I've been getting straight crashes for a while to do with hovering above modulated sliders, and constructing the modulation dragger / info popup. Anyway Claude has helped find a fix for this. I'll post the crash report then Claude's answer and fix:

Crash report:

Thread 0 Crashed:: JUCE Message Thread Dispatch queue: com.apple.main-thread
0   HISE                          	       0x104e7e034 hise::MatrixIds::Helpers::IntensityTextConverter::IntensityTextConverter(hise::MatrixIds::Helpers::IntensityTextConverter::ConstructData const&) + 80
1   HISE                          	       0x104c8cd48 hise::HiSlider::HoverPopup::rebuild() + 1652
2   HISE                          	       0x104c8c498 hise::HiSlider::HoverPopup::HoverPopup(hise::HiSlider&, juce::ValueTree const&, juce::String const&, juce::Array<int, juce::DummyCriticalSection, 0> const&, juce::StringArray const&, hise::HiSlider::HoverPopupLookandFeel::PositionData const&, bool) + 3352
3   HISE                          	       0x104c90f1c hise::HiSlider::ModUpdater::onExclusiveSourceSelection(hise::HiSlider::ModUpdater&, int) + 532
4   HISE                          	       0x104c928b4 hise::SafeLambda<hise::HiSlider::ModUpdater, void, int>::call(int) + 60
5   HISE                          	       0x104c89b0c hise::HiSlider::setup(hise::Processor*, int, juce::String const&) + 1600
6   HISE     

FIX in MacroControlledComponents.cpp:

The bug is here:
onExclusiveSourceSelection is called during setup() via setUpdateFunction() → container->currentMatrixSourceBroadcaster.addListener(*this, ModUpdater::onExclusiveSourceSelection) which fires immediately.
At that point during a content rebuild, slider.getProcessor() may still be valid but mod->getIntensityTextConstructData() is returning a ConstructData struct with a null or invalid member - specifically at offset +80 into the constructor, which is the 3rd or 4th member being initialised.
The fix for Christoph is that onExclusiveSourceSelection should not create a HoverPopup during setup() - it needs a guard:

void HiSlider::ModUpdater::onExclusiveSourceSelection(ModUpdater& mu, int index)
{
    // Guard: don't rebuild hover popup if component isn't visible yet
    if(!mu.parent.isShowing())
        return;
        
    // ... rest of function
}

EDIT - Bit more info:

• Crash is at cd.connectedSlider = parent.getComponent()
• During compile/rebuild, parent.getComponent() returns a pointer to a component that's being destroyed
• Component::SafePointer constructor tries to register with the component's ComponentVTable which is already partially destroyed
• Fix: null check parent.getComponent() before constructing, or defer HoverPopup creation until after rebuild is complete

void HiSlider::ModUpdater::onExclusiveSourceSelection(ModUpdater& mu, int index)
{
    auto& slider = mu.parent;
    
    if(!slider.isShowing())
        return;
        
    auto matrixData = MatrixIds::Helpers::getMatrixDataFromGlobalContainer(slider.getProcessor()->getMainController());
    auto targetId = slider.getProcessor()->getModulationTargetId(slider.getParameter());
    auto hasConnection = MatrixIds::Helpers::getConnection(matrixData, index, targetId).isValid();

    if (hasConnection)
    {
        mu.currentExlusiveIndex = index;
        Array<int> connectedSources;
        connectedSources.add(index);
        StringArray allSources, sourceList;
        MatrixIds::Helpers::fillModSourceList(slider.getProcessor()->getMainController(), allSources);
        sourceList.add(allSources[index]);

        if (auto pd = slider.getHoverPopupLookAndFeel().getModulatorDragData(slider, sourceList))
            slider.currentHoverPopup = new HoverPopup(slider, matrixData, targetId, connectedSources, sourceList, pd, true);
    }
    else
    {
        mu.currentExlusiveIndex = -1;
        slider.currentHoverPopup = nullptr;
    }
}

[Oli Ullmann]

@DanH
In which DAW does your plug-in crash?

[DanH]

@Oli-Ullmann this is in Hise itself

[Oli Ullmann]

@DanH
Oh, ok. That hasn't happened to me yet. I'll test it thoroughly again. Thank you.

[DanH]

@Oli-Ullmann doesn't happen in a small project, just my big one, but hopefully found the culprit. drag and dropping components in the component list could also trigger the crash....