Merge pull request #15535 from daschuer/gh15533

Fix debug assert violation when building without stem support

Author: acolombier

src/skin/legacy/legacyskinparser.cpp

@@ -579,13 +579,11 @@ QList<QWidget*> LegacySkinParser::parseNode(const QDomElement& node) {
         result = wrapWidget(parseLabelWidget<WNumberDb>(node));
     } else if (nodeName == "Label") {
         result = wrapWidget(parseLabelWidget<WLabel>(node));
-    }
+    } else if (nodeName == "StemLabel") {
 #ifdef __STEM__
-    else if (nodeName == "StemLabel") {
         result = wrapWidget(parseStemLabelWidget(node));
-    }
 #endif
-    else if (nodeName == "Knob") {
+    } else if (nodeName == "Knob") {
         result = wrapWidget(parseStandardWidget<WKnob>(node));
     } else if (nodeName == "KnobComposed") {
         result = wrapWidget(parseStandardWidget<WKnobComposed>(node));

src/widget/weffectchainpresetselector.cpp

@@ -31,13 +31,20 @@ void WEffectChainPresetSelector::setup(const QDomNode& node, const SkinContext&
     m_pChain = EffectWidgetUtils::getEffectChainFromNode(
             node, context, m_pEffectsManager);
 
+#ifdef __STEM__
     VERIFY_OR_DEBUG_ASSERT(m_pChain != nullptr) {
         SKIN_WARNING(node,
                 context,
                 QStringLiteral("EffectChainPresetSelector node could not "
                                "attach to EffectChain"));
         return;
     }
+#else
+    if (m_pChain == nullptr) {
+        // This happens if the skin has stem nodes but Mixxx has no stem support.
+        return;
+    }
+#endif
 
     auto* pQuickEffectChain = qobject_cast<QuickEffectChain*>(m_pChain.data());
     if (pQuickEffectChain) {