Save custom data for plugin bridges

Fixes #611

source/backend/CarlaPlugin.hpp

@@ -262,6 +262,13 @@ public:
      */
     const CustomData& getCustomData(const uint32_t index) const noexcept;
 
+    /*!
+     * Give the plugin a change to update its custom data sets.
+     *
+     * @see getCustomDataCount() and getCustomData()
+     */
+    virtual void updateCustomData() noexcept;
+
     /*!
      * Get the complete plugin chunk data into @a dataPtr.
      *

source/backend/engine/CarlaEngineBridge.cpp

@@ -764,7 +764,9 @@ public:
                 const uint32_t valueSize(fShmNonRtClientControl.readUInt());
                 char valueStr[valueSize+1];
                 carla_zeroChars(valueStr, valueSize+1);
-                fShmNonRtClientControl.readCustomData(valueStr, valueSize);
+
+                if (valueSize > 0)
+                    fShmNonRtClientControl.readCustomData(valueStr, valueSize);
 
                 if (plugin != nullptr && plugin->isEnabled())
                     plugin->setCustomData(typeStr, keyStr, valueStr, true);

source/backend/plugin/CarlaPlugin.cpp

@@ -269,6 +269,10 @@ const CustomData& CarlaPlugin::getCustomData(const uint32_t index) const noexcep
     return pData->custom.getAt(index, kCustomDataFallback);
 }
 
+void CarlaPlugin::updateCustomData() noexcept
+{
+}
+
 std::size_t CarlaPlugin::getChunkData(void** const dataPtr) noexcept
 {
     CARLA_SAFE_ASSERT_RETURN(dataPtr != nullptr, 0);
@@ -603,6 +607,8 @@ const CarlaStateSave& CarlaPlugin::getStateSave(const bool callPrepareForSave)
     // ---------------------------------------------------------------
     // Custom Data
 
+    updateCustomData();
+
     for (LinkedList<CustomData>::Itenerator it = pData->custom.begin2(); it.valid(); it.next())
     {
         const CustomData& cData(it.getValue(kCustomDataFallback));

source/backend/plugin/CarlaPluginBridge.cpp

@@ -477,7 +477,10 @@ public:
     // -------------------------------------------------------------------
     // Information (current data)
 
-    // TODO - missing getCustomData
+    void updateCustomData() noexcept override
+    {
+        waitForSaved();
+    }
 
     std::size_t getChunkData(void** const dataPtr) noexcept override
     {
@@ -816,7 +819,9 @@ public:
             fShmNonRtClientControl.writeCustomData(key, keyLen);
 
             fShmNonRtClientControl.writeUInt(valueLen);
-            fShmNonRtClientControl.writeCustomData(value, valueLen);
+
+            if (valueLen > 0)
+                fShmNonRtClientControl.writeCustomData(value, valueLen);
 
             fShmNonRtClientControl.commitWrite();
         }