From c3ee0aa669b9bdd5e216e14ff084b1b5747e0efd Mon Sep 17 00:00:00 2001
From: Piotr Sawicki <sawickipiotr@outlook.com>
Date: Fri, 31 Jul 2026 17:55:35 +0200
Subject: [PATCH] [mypyc] Fix inconsistent vtable method prefix

---
 mypyc/codegen/emitclass.py           |  4 +---
 mypyc/test-data/run-multimodule.test | 29 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/mypyc/codegen/emitclass.py b/mypyc/codegen/emitclass.py
index 9ecdea4327d9..ba48a24643b7 100644
--- a/mypyc/codegen/emitclass.py
+++ b/mypyc/codegen/emitclass.py
@@ -608,9 +608,7 @@ def generate_vtable(
         method = entry.shadow_method if shadow and entry.shadow_method else entry.method
         emitter.emit_line(
             "(CPyVTableItem){}{}{},".format(
-                emitter.get_group_prefix(entry.method.decl),
-                NATIVE_PREFIX,
-                method.cname(emitter.names),
+                emitter.get_group_prefix(method.decl), NATIVE_PREFIX, method.cname(emitter.names)
             )
         )
 
diff --git a/mypyc/test-data/run-multimodule.test b/mypyc/test-data/run-multimodule.test
index 672a726ae985..fed4d3606ed9 100644
--- a/mypyc/test-data/run-multimodule.test
+++ b/mypyc/test-data/run-multimodule.test
@@ -2019,3 +2019,32 @@ class Child(Parent):
 [file driver.py]
 from native import test
 test()
+
+[case testCompiledSubclassOfCompiledBaseThatAllowsInterpretedSubclasses]
+from mypy_extensions import mypyc_attr
+
+from other import CompiledBase
+
+class CompiledSubclass(CompiledBase):
+    def value(self) -> int:
+        return 1
+
+@mypyc_attr(allow_interpreted_subclasses=True)
+class CompiledSubclassThatAllowsInterpreted(CompiledBase):
+    def value(self) -> int:
+        return 2
+
+def test_compiled_subclasses_of_compiled_base_that_allows_interpreted_subclasses() -> None:
+    c1 = CompiledSubclass()
+    assert c1.value() == 1
+
+    c2 = CompiledSubclassThatAllowsInterpreted()
+    assert c2.value() == 2
+
+[file other.py]
+from mypy_extensions import mypyc_attr
+
+@mypyc_attr(allow_interpreted_subclasses=True)
+class CompiledBase:
+    def value(self) -> int:
+        raise NotImplementedError