Fix constant type collection (#2505)

crates/libs/bindgen/src/standalone.rs

@@ -67,8 +67,10 @@ fn standalone_imp(gen: &mut Gen, names: &[&str]) -> String {
             .find(|field| gen.reader.field_name(*field) == type_name.name)
         {
             constants.insert(field);
-            gen.reader
-                .type_collect_standalone(&gen.reader.field_type(field, None), &mut types);
+            gen.reader.type_collect_standalone(
+                &gen.reader.field_type(field, None).to_const_type(),
+                &mut types,
+            );
         }
 
         if let Some(field) = gen

crates/tests/standalone/build.rs

@@ -127,6 +127,15 @@ fn main() {
         "src/b_overloads.rs",
         &["Windows.Win32.NetworkManagement.NetManagement.AE_RESACCESS"],
     );
+
+    // Ensures that constant types are properly collected
+    write_sys(
+        "src/b_constant_types.rs",
+        &[
+            "Windows.Win32.UI.WindowsAndMessaging.IDC_UPARROW",
+            "Windows.Win32.Security.Cryptography.CMC_ADD_ATTRIBUTES",
+        ],
+    );
 }
 
 fn write_sys(filename: &str, apis: &[&str]) {

crates/tests/standalone/src/b_constant_types.rs

@@ -0,0 +1,13 @@
+// Bindings generated by `windows-bindgen` 0.49.0
+
+#![allow(
+    non_snake_case,
+    non_upper_case_globals,
+    non_camel_case_types,
+    dead_code,
+    clippy::all
+)]
+pub const CMC_ADD_ATTRIBUTES: PCSTR = 63i32 as _;
+pub const IDC_UPARROW: PCWSTR = 32516u16 as _;
+pub type PCSTR = *const u8;
+pub type PCWSTR = *const u16;

crates/tests/standalone/src/lib.rs

@@ -5,6 +5,7 @@ mod b_arch;
 mod b_arch_dependencies;
 mod b_bstr;
 mod b_calendar;
+mod b_constant_types;
 mod b_depends;
 mod b_enumeration;
 mod b_enumerator;