From 568597bddc205378de7b5f37ce2c4c15c8d397f3 Mon Sep 17 00:00:00 2001
From: Setsugennoao <41454651+Setsugennoao@users.noreply.github.com>
Date: Fri, 3 Nov 2023 01:29:22 +0100
Subject: [PATCH] vapoursynth: Fix VSScript DLL loading

We do this by first trying to fetch its location from the registry, then PATH
---
 src/vapoursynth_wrap.cpp | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/vapoursynth_wrap.cpp b/src/vapoursynth_wrap.cpp
index d0f7f0173..addb3c6ac 100644
--- a/src/vapoursynth_wrap.cpp
+++ b/src/vapoursynth_wrap.cpp
@@ -32,6 +32,13 @@
 
 #ifdef _WIN32
 #define VSSCRIPT_SO "vsscript.dll"
+
+#ifdef _WIN64
+#define VS_INSTALL_REGKEY L"Software\\VapourSynth"
+#else
+#define VS_INSTALL_REGKEY L"Software\\VapourSynth-32"
+#endif
+
 #else
 #ifdef __APPLE__
 #define VSSCRIPT_SO "libvapoursynth-script.dylib"
@@ -61,11 +68,39 @@ VapourSynthWrapper::VapourSynthWrapper() {
 	// VSScript assumes it's only loaded once, so unlike AVS we can't unload it when the refcount reaches zero
 	if (!vs_loaded) {
 #ifdef _WIN32
+
+		std::wstring vsscriptDLLpath = L"";
+
+		HKEY hKey;
+		LONG lRes = RegOpenKeyEx(HKEY_CURRENT_USER, VS_INSTALL_REGKEY, 0, KEY_READ, &hKey);
+
+		if (lRes != ERROR_SUCCESS) {
+			lRes = RegOpenKeyEx(HKEY_LOCAL_MACHINE, VS_INSTALL_REGKEY, 0, KEY_READ, &hKey);
+		}
+
+		if (lRes == ERROR_SUCCESS) {
+			WCHAR szBuffer[512];
+			DWORD dwBufferSize = sizeof(szBuffer);
+			ULONG nError;
+
+			nError = RegQueryValueEx(hKey, L"VSScriptDLL", 0, nullptr, (LPBYTE)szBuffer, &dwBufferSize);
+			RegCloseKey(hKey);
+
+			if (nError == ERROR_SUCCESS)
+				vsscriptDLLpath = szBuffer;
+		}
+
+		if (vsscriptDLLpath.length()) {
+			hLib = LoadLibraryW(vsscriptDLLpath.c_str());
+		}
+
+		if (!hLib) {
 #define CONCATENATE(x, y) x ## y
 #define _Lstr(x) CONCATENATE(L, x)
-		hLib = LoadLibraryW(_Lstr(VSSCRIPT_SO));
+			hLib = LoadLibraryW(_Lstr(VSSCRIPT_SO));
 #undef _Lstr
 #undef CONCATENATE
+		}
 #else
 		hLib = dlopen(VSSCRIPT_SO, DLOPEN_FLAGS);
 #endif