Harden reg-free class activation (#3365)

crates/libs/core/src/imp/com_bindings.rs

@@ -240,5 +240,6 @@ impl IWeakReferenceSource_Vtbl {
 }
 impl windows_core::RuntimeName for IWeakReferenceSource {}
 pub const JSCRIPT_E_CANTEXECUTE: windows_core::HRESULT = windows_core::HRESULT(0x89020001_u32 as _);
+pub const REGDB_E_CLASSNOTREG: windows_core::HRESULT = windows_core::HRESULT(0x80040154_u32 as _);
 pub const RPC_E_DISCONNECTED: windows_core::HRESULT = windows_core::HRESULT(0x80010108_u32 as _);
 pub const TYPE_E_TYPEMISMATCH: windows_core::HRESULT = windows_core::HRESULT(0x80028CA0_u32 as _);

crates/libs/core/src/imp/factory_cache.rs

@@ -106,14 +106,18 @@ pub fn factory<C: crate::RuntimeName, I: Interface>() -> crate::Result<I> {
     // can ultimately return this error information if all else fails.
     let original: crate::Error = code.into();
 
-    // Now attempt to find the factory's implementation heuristically.
-    if let Some(i) = search_path(C::NAME, |library| unsafe {
-        get_activation_factory(library, &name)
-    }) {
-        i.cast()
-    } else {
-        Err(original)
+    // Reg-free activation should only be attempted if the class is not registered.
+    // It should not be attempted if the class is registered but fails to activate.
+    if code == REGDB_E_CLASSNOTREG {
+        // Now attempt to find the factory's implementation heuristically.
+        if let Some(i) = search_path(C::NAME, |library| unsafe {
+            get_activation_factory(library, &name)
+        }) {
+            return i.cast();
+        }
     }
+
+    Err(original)
 }
 
 // Remove the suffix until a match is found appending `.dll\0` at the end

crates/tools/bindings/src/core_com.txt

@@ -6,6 +6,7 @@
 
 --filter
     Windows.Win32.Foundation.CO_E_NOTINITIALIZED
+    Windows.Win32.Foundation.REGDB_E_CLASSNOTREG
     Windows.Win32.Foundation.E_BOUNDS
     Windows.Win32.Foundation.E_INVALIDARG
     Windows.Win32.Foundation.E_NOINTERFACE