Add ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR (testing)

source/backend/CarlaBackend.h

@@ -1056,10 +1056,16 @@ typedef enum {
      */
     ENGINE_OPTION_PATH_RESOURCES = 16,
 
+    /*!
+     * Prevent bad plugin and UI behaviour.
+     * @note: Linux only
+     */
+    ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR = 17,
+
     /*!
      * Set frontend winId, used to define as parent window for plugin UIs.
      */
-    ENGINE_OPTION_FRONTEND_WIN_ID = 17
+    ENGINE_OPTION_FRONTEND_WIN_ID = 18
 
 } EngineOption;
 

source/backend/CarlaEngine.hpp

@@ -251,6 +251,7 @@ struct EngineOptions {
     const char* binaryDir;
     const char* resourceDir;
 
+    bool preventBadBehaviour;
     uintptr_t frontendWinId;
 
 #ifndef DOXYGEN

source/backend/CarlaStandalone.cpp

@@ -780,6 +780,8 @@ bool carla_engine_init(const char* driverName, const char* clientName)
     if (gStandalone.engineOptions.resourceDir != nullptr && gStandalone.engineOptions.resourceDir[0] != '\0')
         gStandalone.engine->setOption(CB::ENGINE_OPTION_PATH_RESOURCES, 0, gStandalone.engineOptions.resourceDir);
 
+    gStandalone.engine->setOption(CB::ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR, gStandalone.engineOptions.preventBadBehaviour ? 1 : 0,  nullptr);
+
     if (gStandalone.engineOptions.frontendWinId != 0)
     {
         char strBuf[STR_MAX+1];
@@ -884,6 +886,9 @@ bool carla_engine_init_bridge(const char audioBaseName[6+1], const char rtBaseNa
     if (const char* const resourceDir = std::getenv("ENGINE_OPTION_PATH_RESOURCES"))
         gStandalone.engine->setOption(CB::ENGINE_OPTION_PATH_RESOURCES,  0, resourceDir);
 
+    if (const char* const preventBadBehaviour = std::getenv("ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR"))
+        gStandalone.engine->setOption(CB::ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR, (std::strcmp(preventBadBehaviour, "true") == 0) ? 1 : 0, nullptr);
+
     if (const char* const frontendWinId = std::getenv("ENGINE_OPTION_FRONTEND_WIN_ID"))
         gStandalone.engine->setOption(CB::ENGINE_OPTION_FRONTEND_WIN_ID, 0, frontendWinId);
 
@@ -1119,6 +1124,11 @@ void carla_set_engine_option(EngineOption option, int value, const char* valueSt
         gStandalone.engineOptions.resourceDir = carla_strdup_safe(valueStr);
         break;
 
+    case CB::ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR:
+        CARLA_SAFE_ASSERT_RETURN(value == 0 || value == 1,);
+        gStandalone.engineOptions.preventBadBehaviour = (value != 0);
+        break;
+
     case CB::ENGINE_OPTION_FRONTEND_WIN_ID:
         CARLA_SAFE_ASSERT_RETURN(valueStr != nullptr && valueStr[0] != '\0',);
         const long long winId(std::strtoll(valueStr, nullptr, 16));

source/backend/engine/CarlaEngine.cpp

@@ -1352,6 +1352,21 @@ void CarlaEngine::setOption(const EngineOption option, const int value, const ch
         pData->options.resourceDir = carla_strdup_safe(valueStr);
         break;
 
+    case ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR:
+        CARLA_SAFE_ASSERT_RETURN(pData->options.binaryDir != nullptr && pData->options.binaryDir[0] != '\0',);
+#ifdef CARLA_OS_LINUX
+        if (value != 0)
+        {
+            CarlaString interposerPath(CarlaString(pData->options.binaryDir) + CARLA_OS_SEP_STR "libcarlainterposer.so");
+            ::setenv("LD_PRELOAD", interposerPath.buffer(), 1);
+        }
+        else
+        {
+            ::unsetenv("LD_PRELOAD");
+        }
+#endif
+        break;
+
     case ENGINE_OPTION_FRONTEND_WIN_ID:
         CARLA_SAFE_ASSERT_RETURN(valueStr != nullptr && valueStr[0] != '\0',);
         const long long winId(std::strtoll(valueStr, nullptr, 16));

source/backend/engine/CarlaEngineData.cpp

@@ -211,6 +211,7 @@ EngineOptions::EngineOptions() noexcept
       pathSFZ(nullptr),
       binaryDir(nullptr),
       resourceDir(nullptr),
+      preventBadBehaviour(false),
       frontendWinId(0) {}
 
 EngineOptions::~EngineOptions() noexcept

source/backend/plugin/CarlaPluginThread.cpp

@@ -235,9 +235,16 @@ void CarlaPluginThread::run()
     else
         carla_setenv("ENGINE_OPTION_PATH_RESOURCES", "");
 
+    carla_setenv("ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR", bool2str(options.preventBadBehaviour));
+
     std::snprintf(strBuf, STR_MAX, P_UINTPTR, options.frontendWinId);
     carla_setenv("ENGINE_OPTION_FRONTEND_WIN_ID", strBuf);
 
+#ifdef CARLA_OS_LINUX
+    const char* const oldPreload(std::getenv("LD_PRELOAD"));
+    ::unsetenv("LD_PRELOAD");
+#endif
+
     switch (fMode)
     {
     case PLUGIN_THREAD_NULL:
@@ -280,6 +287,11 @@ void CarlaPluginThread::run()
 
     fProcess->start(arguments);
 
+#ifdef CARLA_OS_LINUX
+    if (oldPreload != nullptr)
+        ::setenv("LD_PRELOAD", oldPreload, 1);
+#endif
+
     sEnvMutex.unlock();
 
     switch (fMode)

source/carla_backend.py

@@ -777,8 +777,12 @@ ENGINE_OPTION_PATH_BINARIES = 15
 # @note Must be set for some internal plugins to work
 ENGINE_OPTION_PATH_RESOURCES = 16
 
+# Prevent bad plugin and UI behaviour.
+# @note: Linux only
+ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR = 17
+
 # Set frontend winId, used to define as parent window for plugin UIs.
-ENGINE_OPTION_FRONTEND_WIN_ID = 17
+ENGINE_OPTION_FRONTEND_WIN_ID = 18
 
 # ------------------------------------------------------------------------------------------------------------
 # Engine Process Mode
@@ -1315,6 +1319,7 @@ class CarlaHostMeta(QObject):
         self.forceStereo         = False
         self.preferPluginBridges = False
         self.preferUIBridges     = False
+        self.preventBadBehaviour = False
         self.uisAlwaysOnTop      = False
         self.maxParameters       = 0
         self.uiBridgesTimeout    = 0

source/carla_host.py

@@ -1347,12 +1347,16 @@ def setHostSettings(host):
     # kdevelop likes this :)
     if False: host = CarlaHostMeta()
 
+    # TEST
+    host.preventBadBehaviour = True
+
     host.set_engine_option(ENGINE_OPTION_FORCE_STEREO,          host.forceStereo,         "")
     host.set_engine_option(ENGINE_OPTION_PREFER_PLUGIN_BRIDGES, host.preferPluginBridges, "")
     host.set_engine_option(ENGINE_OPTION_PREFER_UI_BRIDGES,     host.preferUIBridges,     "")
     host.set_engine_option(ENGINE_OPTION_UIS_ALWAYS_ON_TOP,     host.uisAlwaysOnTop,      "")
     host.set_engine_option(ENGINE_OPTION_MAX_PARAMETERS,        host.maxParameters,       "")
     host.set_engine_option(ENGINE_OPTION_UI_BRIDGES_TIMEOUT,    host.uiBridgesTimeout,    "")
+    host.set_engine_option(ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR, host.preventBadBehaviour, "")
 
     if host.isPlugin:
         return

source/utils/CarlaBackendUtils.hpp

@@ -324,6 +324,8 @@ const char* EngineOption2Str(const EngineOption option) noexcept
         return "ENGINE_OPTION_PATH_BINARIES";
     case ENGINE_OPTION_PATH_RESOURCES:
         return "ENGINE_OPTION_PATH_RESOURCES";
+    case ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR:
+        return "ENGINE_OPTION_PREVENT_BAD_BEHAVIOUR";
     case ENGINE_OPTION_FRONTEND_WIN_ID:
         return "ENGINE_OPTION_FRONTEND_WIN_ID";
     }