From b939b6c9f7e5f3c0c54144738c1a23dc32165679 Mon Sep 17 00:00:00 2001
From: Andrei Homescu <ah@immunant.com>
Date: Mon, 24 Nov 2025 22:50:14 -0800
Subject: [PATCH 1/3] c2rust-refactor: Implement deep structural comparison of
 ADTs by comparing all variants

---
 c2rust-refactor/src/context.rs | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/c2rust-refactor/src/context.rs b/c2rust-refactor/src/context.rs
index 3d0ced31bf..90297d46e1 100644
--- a/c2rust-refactor/src/context.rs
+++ b/c2rust-refactor/src/context.rs
@@ -1334,6 +1334,10 @@ impl<'a, 'tcx, 'b> TypeCompare<'a, 'tcx, 'b> {
 
         match (&ty1.kind(), &ty2.kind()) {
             (TyKind::Adt(def1, substs1), TyKind::Adt(def2, substs2)) => {
+                if def1.adt_kind() != def2.adt_kind() {
+                    return false;
+                }
+
                 if substs1.types().count() != substs2.types().count()
                     || !substs1
                         .types()
@@ -1366,15 +1370,21 @@ impl<'a, 'tcx, 'b> TypeCompare<'a, 'tcx, 'b> {
                     return true;
                 }
 
-                def1.all_fields().count() == def2.all_fields().count()
+                def1.variants().len() == def2.variants().len()
                     && def1
-                        .all_fields()
-                        .zip(def2.all_fields())
-                        .all(|(field1, field2)| {
-                            field1.ident(tcx).unnamed_equiv(&field2.ident(tcx))
-                                && (!match_vis || field1.vis == field2.vis)
-                                && self.structural_eq_defs_impl(
-                                    field1.did, field2.did, match_vis, seen,
+                        .variants()
+                        .iter()
+                        .zip(def2.variants().iter())
+                        .all(|(var1, var2)| {
+                            var1.fields.len() == var2.fields.len()
+                                && var1.fields.iter().zip(var2.fields.iter()).all(
+                                    |(field1, field2)| {
+                                        field1.ident(tcx).unnamed_equiv(&field2.ident(tcx))
+                                            && (!match_vis || field1.vis == field2.vis)
+                                            && self.structural_eq_defs_impl(
+                                                field1.did, field2.did, match_vis, seen,
+                                            )
+                                    },
                                 )
                         })
             }

From a72e2e94ce6c3d9a3bd98e53c22eee7afefdd00e Mon Sep 17 00:00:00 2001
From: Andrei Homescu <ah@immunant.com>
Date: Wed, 3 Dec 2025 17:37:18 -0800
Subject: [PATCH 2/3] tests: integration: Enable reorganize_definitions for
 nginx

---
 tests/integration/tests/nginx/conf.yml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/integration/tests/nginx/conf.yml b/tests/integration/tests/nginx/conf.yml
index 81b6cb1ca0..24b91aa022 100644
--- a/tests/integration/tests/nginx/conf.yml
+++ b/tests/integration/tests/nginx/conf.yml
@@ -15,12 +15,14 @@ cargo.refactor:
 transpile:
   autogen: true
   # blocked on https://github.com/immunant/c2rust/issues/266
-  # tflags: --reorganize-definitions
+  tflags: --reorganize-definitions --disable-refactoring
   binary: nginx
 
 refactor:
   autogen: true
   transforms:
+    - rename_unnamed
+    - reorganize_definitions
     - remove_unused_labels
     - remove_literal_suffixes
     - convert_cast_as_ptr

From b1e71cadc012415064652cebf899a54d222eb1ce Mon Sep 17 00:00:00 2001
From: Khyber Sen <kkysen@gmail.com>
Date: Mon, 8 Dec 2025 05:36:37 -0800
Subject: [PATCH 3/3] refactor: add comment explaining the variant and field
 comparison in `fn structural_eq_tys_impl`

---
 c2rust-refactor/src/context.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/c2rust-refactor/src/context.rs b/c2rust-refactor/src/context.rs
index 90297d46e1..ff63b923b4 100644
--- a/c2rust-refactor/src/context.rs
+++ b/c2rust-refactor/src/context.rs
@@ -1370,6 +1370,9 @@ impl<'a, 'tcx, 'b> TypeCompare<'a, 'tcx, 'b> {
                     return true;
                 }
 
+                // Iterate separately over the variants and fields (as opposed to the `.all_fields()` flat map).
+                // Otherwise, we may find a false equivalence for empty variants,
+                // or, in general, the flattened iterator could have the same elements but different variant boundaries.
                 def1.variants().len() == def2.variants().len()
                     && def1
                         .variants()