Add from_raw to windows-registry (microsoft#3034)

crates/libs/core/src/handles.rs

@@ -19,7 +19,8 @@ impl<T: Free> Owned<T> {
     /// Takes ownership of the handle.
     ///
     /// # Safety
-    /// The handle must be owned by the caller and safe to free.    
+    ///
+    /// The handle must be owned by the caller and safe to free.
     pub unsafe fn new(x: T) -> Self {
         Self(x)
     }

crates/libs/registry/src/key.rs

@@ -37,6 +37,16 @@ impl Key {
         win32_error(result).map(|_| Self(handle))
     }
 
+    /// Constructs a registry key from an existing handle.
+    ///
+    /// # Safety
+    ///
+    /// This function takes ownership of the handle.
+    /// The handle must be owned by the caller and safe to free with `RegCloseKey`.
+    pub unsafe fn from_raw(handle: isize) -> Self {
+        Self(handle)
+    }
+
     /// Returns the underlying registry key handle.
     pub fn as_raw(&self) -> isize {
         self.0

crates/tests/registry/tests/sys_interop.rs

@@ -11,11 +11,15 @@ fn sys_interop() -> Result<()> {
     key.set_u32("2", 2)?;
     key.set_u32("3", 3)?;
 
+    let raw: HKEY = key.as_raw();
+    std::mem::forget(key);
+    let owned = unsafe { Key::from_raw(raw) };
+
     let mut count = 0;
 
     unsafe {
         RegQueryInfoKeyW(
-            key.as_raw(),
+            owned.as_raw(),
             std::ptr::null_mut(),
             std::ptr::null_mut(),
             std::ptr::null_mut(),

crates/tests/registry/tests/windows_interop.rs

@@ -11,11 +11,15 @@ fn windows_interop() -> Result<()> {
     key.set_u32("2", 2)?;
     key.set_u32("3", 3)?;
 
+    let raw = HKEY(key.as_raw());
+    std::mem::forget(key);
+    let owned = unsafe { Key::from_raw(raw.0) };
+
     let mut count = 0;
 
     unsafe {
         RegQueryInfoKeyW(
-            HKEY(key.as_raw()),
+            HKEY(owned.as_raw()),
             PWSTR::null(),
             None,
             None,