Only run LS in bridge mode when absolutely necessary

source/backend/engine/CarlaEngine.cpp

@@ -491,9 +491,18 @@ bool CarlaEngine::addPlugin(const BinaryType btype, const PluginType ptype,
                 preferBridges = true;
         }
         // FIXME: linuxsampler inside carla-rack/patchbay plugin has some issues (only last kit makes noise)
-        else if (getType() == kEngineTypePlugin)
+        else if (getType() == kEngineTypePlugin && (ptype == PLUGIN_GIG || ptype == PLUGIN_SFZ))
         {
-            if (ptype == PLUGIN_GIG || ptype == PLUGIN_SFZ)
+            // if we're not loading a project consider all is ok
+            if (! pData->loadingProject)
+                pData->firstLinuxSamplerInstance = true;
+
+            // loading a project, revert first status if set
+            else if (pData->firstLinuxSamplerInstance)
+                pData->firstLinuxSamplerInstance = false;
+
+            // now check if bridge is needed
+            if (! pData->firstLinuxSamplerInstance)
                 preferBridges = true;
         }
     }
@@ -1839,6 +1848,10 @@ bool CarlaEngine::loadProjectInternal(juce::XmlDocument& xmlDoc)
         return false;
     }
 
+#ifndef BUILD_BRIDGE
+    const ScopedValueSetter<bool> _svs(pData->loadingProject, true, false);
+#endif
+
     // completely load file
     xmlElement = xmlDoc.getDocumentElement(false);
     CARLA_SAFE_ASSERT_RETURN_ERR(xmlElement != nullptr, "Failed to completely parse project file");

source/backend/engine/CarlaEngineInternal.cpp

@@ -103,6 +103,10 @@ CarlaEngine::ProtectedData::ProtectedData(CarlaEngine* const engine) noexcept
       callbackPtr(nullptr),
       fileCallback(nullptr),
       fileCallbackPtr(nullptr),
+#ifndef BUILD_BRIDGE
+      firstLinuxSamplerInstance(true),
+      loadingProject(false),
+#endif
       hints(0x0),
       bufferSize(0),
       sampleRate(0.0),

source/backend/engine/CarlaEngineInternal.hpp

@@ -173,6 +173,12 @@ struct CarlaEngine::ProtectedData {
     FileCallbackFunc fileCallback;
     void*            fileCallbackPtr;
 
+#ifndef BUILD_BRIDGE
+    // special hack for linuxsampler
+    bool firstLinuxSamplerInstance;
+    bool loadingProject;
+#endif
+
     uint     hints;
     uint32_t bufferSize;
     double   sampleRate;

source/backend/plugin/CarlaPluginLinuxSampler.cpp

@@ -33,7 +33,6 @@
 
 #include "juce_core.h"
 
-#include "linuxsampler/EngineFactory.h"
 #include <linuxsampler/Sampler.h>
 
 // -----------------------------------------------------------------------