solve some bugs

app/pluginSupport/OliveClip.cpp

@@ -124,7 +124,15 @@ const std::string &olive::plugin::OliveClipInstance::getFieldOrder() const
 }
 bool olive::plugin::OliveClipInstance::getConnected() const
 {
-	return params_.format() == PixelFormat::INVALID;
+	if (name_ == kOfxImageEffectOutputClipName) {
+		return true;
+	}
+#ifdef OFX_SUPPORTS_OPENGLRENDER
+	if (!input_textures_.isEmpty()) {
+		return true;
+	}
+#endif
+	return !images_.isEmpty();
 }
 double olive::plugin::OliveClipInstance::getUnmappedFrameRate() const
 {

app/pluginSupport/OliveHost.cpp

@@ -71,15 +71,20 @@ void AddPluginPathsFromEnv(OFX::Host::PluginCache *cache, const char *env_var)
 
 void olive::plugin::loadPlugins(QString path)
 {
-	std::shared_ptr<OliveHost> host = std::make_shared<OliveHost>();
-	Current::getInstance().setPluginHost(host);
-
+	std::shared_ptr<OliveHost> host = Current::getInstance().pluginHost();
 	std::shared_ptr<ImageEffect::PluginCache> imageEffectPluginCache =
-		std::make_shared<ImageEffect::PluginCache>(*host);
-	Current::getInstance().setPluginCache(imageEffectPluginCache);
+		Current::getInstance().pluginCache();
 
-	imageEffectPluginCache->registerInCache(
-		*OFX::Host::PluginCache::getPluginCache());
+	if (!host || !imageEffectPluginCache) {
+		host = std::make_shared<OliveHost>();
+		Current::getInstance().setPluginHost(host);
+
+		imageEffectPluginCache = std::make_shared<ImageEffect::PluginCache>(*host);
+		Current::getInstance().setPluginCache(imageEffectPluginCache);
+
+		imageEffectPluginCache->registerInCache(
+			*OFX::Host::PluginCache::getPluginCache());
+	}
 	OFX::Host::PluginCache *cache = OFX::Host::PluginCache::getPluginCache();
 	cache->setPluginHostPath("Olive");
 

app/pluginSupport/OliveHost.h

@@ -53,6 +53,14 @@ public:
 	bool pluginSupported(OFX::Host::ImageEffect::ImageEffectPlugin *plugin,
 		std::string &reason) const override
 	{
+		if (!plugin) {
+			reason = "null plugin";
+			return false;
+		}
+		if (plugin->getContexts().empty()) {
+			reason = "no supported contexts (describe failed)";
+			return false;
+		}
 		return true;
 	};
 

app/pluginSupport/OlivePluginInstance.h

@@ -53,7 +53,8 @@ public:
 	{
 	}
 	OlivePluginInstance(OlivePluginInstance& instance)
-		: Instance(_plugin, *_descriptor, _context, _interactive)
+		: Instance(instance._plugin, *instance._descriptor, instance._context,
+				   instance._interactive)
 	{
 		_clips=instance._clips;
 		_created=instance._created;