Small fixups for jack engine

Signed-off-by: falkTX <falktx@falktx.com>

source/backend/engine/CarlaEngineJack.cpp

@@ -2366,6 +2366,8 @@ public:
         if (pData->options.processMode == ENGINE_PROCESS_MODE_PATCHBAY && ! external)
             return CarlaEngine::getPatchbayPositions(external, count);
 
+        const CarlaMutexLocker cml(fUsedGroups.mutex);
+
         if (const std::size_t maxCount = fUsedGroups.list.count())
         {
             PatchbayPosition* ret;
@@ -2378,8 +2380,6 @@ public:
 
             GroupNameToId groupNameToId;
 
-            const CarlaMutexLocker cml1(fUsedGroups.mutex);
-
             for (LinkedList<GroupNameToId>::Itenerator it = fUsedGroups.list.begin2(); it.valid(); it.next())
             {
                 groupNameToId = it.getValue(kGroupNameToIdFallback);
@@ -2504,7 +2504,7 @@ public:
             for (int i=10; --i >=0;)
             {
                 {
-                    const CarlaMutexLocker cml1(fUsedGroups.mutex);
+                    const CarlaMutexLocker cml(fUsedGroups.mutex);
 
                     if (fUsedGroups.list.count() == 0)
                     {
@@ -2522,6 +2522,15 @@ public:
                 callback(true, true, ENGINE_CALLBACK_IDLE, 0, 0, 0, 0, 0.0f, nullptr);
             }
         }
+        else
+        {
+            const CarlaMutexLocker cml(fUsedGroups.mutex);
+
+            if (fUsedGroups.list.count() != 0)
+                groupId = fUsedGroups.getGroupId(ppos.name);
+            else
+                hasGroups = false;
+        }
 
         if (hasGroups) {
             CARLA_SAFE_ASSERT(groupId != 0);