From 0759c34b7d1c03b0e6cf82ccd8e3e5626255770c Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Thu, 24 Jul 2025 13:42:51 +0200
Subject: [PATCH] VST3: Allow IRunLoop to query itself

For whatever reason renoise_redux.vst3 requires this, and
otherwise complains that the host does not implement IRunLoop
interface, which the plugin already successfully retrieved
to make this query in the first place.
---
 libs/ardour/vst3_host.cc | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/libs/ardour/vst3_host.cc b/libs/ardour/vst3_host.cc
index 65ddacac81..f187a20264 100644
--- a/libs/ardour/vst3_host.cc
+++ b/libs/ardour/vst3_host.cc
@@ -82,6 +82,8 @@ DEF_CLASS_IID (Presonus::IPlugInViewScaling)
 
 #if SMTG_OS_LINUX
 DEF_CLASS_IID (Linux::IRunLoop);
+DEF_CLASS_IID (Linux::ITimerHandler);
+DEF_CLASS_IID (Linux::IEventHandler);
 
 class AVST3Runloop : public Linux::IRunLoop
 {
@@ -212,7 +214,14 @@ public:
 
 	uint32 PLUGIN_API addRef () SMTG_OVERRIDE { return 1; }
 	uint32 PLUGIN_API release () SMTG_OVERRIDE { return 1; }
-	tresult queryInterface (const TUID, void**) SMTG_OVERRIDE { return kNoInterface; }
+
+	tresult queryInterface (const TUID iid, void** obj) SMTG_OVERRIDE {
+		if (FUnknownPrivate::iidEqual (iid, Linux::IRunLoop::iid)) {
+			*obj = this;
+			return kResultOk;
+		}
+		return kNoInterface;
+	}
 
 private:
 	Glib::Threads::Mutex _lock;