Define CUSTOM_DATA_TYPE_PATH and allow it for LV2 as custom data

source/backend/CarlaBackend.h

@@ -463,6 +463,11 @@ static const char* const CUSTOM_DATA_TYPE_BOOLEAN = "http://kxstudio.sf.net/ns/c
  */
 static const char* const CUSTOM_DATA_TYPE_CHUNK = "http://kxstudio.sf.net/ns/carla/chunk";
 
+/*!
+ * Path type URI.
+ */
+static const char* const CUSTOM_DATA_TYPE_PATH = "http://kxstudio.sf.net/ns/carla/path";
+
 /*!
  * Property type URI.
  */

source/backend/plugin/CarlaPluginLV2.cpp

@@ -1536,6 +1536,19 @@ public:
         CARLA_SAFE_ASSERT_RETURN(value != nullptr,);
         carla_debug("CarlaPluginLV2::setCustomData(%s, %s, %s, %s)", type, key, value, bool2str(sendGui));
 
+        if (std::strcmp(type, CUSTOM_DATA_TYPE_PATH) == 0)
+        {
+            if (std::strcmp(key, "file") != 0)
+                return;
+
+            CARLA_SAFE_ASSERT_RETURN(fFilePathURI.isNotEmpty(),);
+            CARLA_SAFE_ASSERT_RETURN(value[0] != '\0',);
+
+            carla_stdout("LV2 file path to send: '%s'", value);
+            writeAtomPath(value, getCustomURID(fFilePathURI));
+            return;
+        }
+
         if (std::strcmp(type, CUSTOM_DATA_TYPE_PROPERTY) == 0)
             return CarlaPlugin::setCustomData(type, key, value, sendGui);
 

source/backend/plugin/CarlaPluginNative.cpp

@@ -795,8 +795,16 @@ public:
         if (std::strcmp(type, CUSTOM_DATA_TYPE_PROPERTY) == 0)
             return CarlaPlugin::setCustomData(type, key, value, sendGui);
 
-        if (std::strcmp(type, CUSTOM_DATA_TYPE_STRING) != 0 && std::strcmp(type, CUSTOM_DATA_TYPE_CHUNK) != 0)
-            return carla_stderr2("CarlaPluginNative::setCustomData(\"%s\", \"%s\", \"%s\", %s) - type is invalid", type, key, value, bool2str(sendGui));
+        if (std::strcmp(type, CUSTOM_DATA_TYPE_PATH) == 0)
+        {
+            CARLA_SAFE_ASSERT_RETURN(std::strcmp(key, "file") == 0,);
+            CARLA_SAFE_ASSERT_RETURN(value[0] != '\0',);
+        }
+        else if (std::strcmp(type, CUSTOM_DATA_TYPE_STRING) != 0 && std::strcmp(type, CUSTOM_DATA_TYPE_CHUNK) != 0)
+        {
+            return carla_stderr2("CarlaPluginNative::setCustomData(\"%s\", \"%s\", \"%s\", %s) - type is invalid xa",
+                                 type, key, value, bool2str(sendGui));
+        }
 
         if (std::strcmp(type, CUSTOM_DATA_TYPE_CHUNK) == 0)
         {