From e7e900dd3fc4978d090b9ba88c3fa9134490969f Mon Sep 17 00:00:00 2001
From: Kenny Kerr <kenny@kennykerr.ca>
Date: Fri, 12 Jan 2024 10:33:10 -0600
Subject: [PATCH] retval

---
 crates/libs/bindgen/src/metadata.rs      | 8 ++++++++
 crates/samples/windows/shell/src/main.rs | 7 ++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/crates/libs/bindgen/src/metadata.rs b/crates/libs/bindgen/src/metadata.rs
index b966e20494..ffe4b93e06 100644
--- a/crates/libs/bindgen/src/metadata.rs
+++ b/crates/libs/bindgen/src/metadata.rs
@@ -181,6 +181,14 @@ impl Signature {
     }
 
     fn is_retval(&self) -> bool {
+        // First we check whether there's an actual retval parameter.
+        if let Some(param) = self.params.last() {
+            if param.def.has_attribute("RetValAttribute") {
+                return true;
+            }
+        }
+
+        // Then we see if we can infer retval-like behavior more conservatively.
         self.params.last().map_or(false, |param| param.is_retval())
             && self.params[..self.params.len() - 1].iter().all(|param| {
                 let flags = param.def.flags();
diff --git a/crates/samples/windows/shell/src/main.rs b/crates/samples/windows/shell/src/main.rs
index 3e4287ef18..513e8d3ed8 100644
--- a/crates/samples/windows/shell/src/main.rs
+++ b/crates/samples/windows/shell/src/main.rs
@@ -42,20 +42,17 @@ fn shell_execute_from_explorer(
 fn find_desktop_folder_view<T: Interface>() -> Result<T> {
     unsafe {
         let windows: IShellWindows = CoCreateInstance(&ShellWindows, None, CLSCTX_ALL)?;
-        let mut dispatch = None;
         let mut handle = 0;
 
-        // TODO: find out why this retval isn't kicking in
-        windows.FindWindowSW(
+        let desktop = windows.FindWindowSW(
             &VARIANT::from(CSIDL_DESKTOP),
             &VARIANT::default(),
             SWC_DESKTOP,
             &mut handle,
             SWFO_NEEDDISPATCH,
-            &mut dispatch,
         )?;
 
-        let provider: IServiceProvider = dispatch.unwrap().cast()?;
+        let provider: IServiceProvider = desktop.cast()?;
         let browser: IShellBrowser = provider.QueryService(&SID_STopLevelBrowser)?;
         let view = browser.QueryActiveShellView()?;
         view.cast()