From 3364bf4e803f2f132ae822db327c30d3ec9006f5 Mon Sep 17 00:00:00 2001
From: sabiwara <sabiwara@gmail.com>
Date: Fri, 6 Sep 2024 11:04:53 +0900
Subject: [PATCH] Fix: Macro.expand/2 should not expand __ENV__ on :match
 context

---
 lib/elixir/lib/macro.ex                      |  4 ++--
 lib/elixir/test/elixir/macro_test.exs        | 10 +++++++++
 lib/ex_unit/test/ex_unit/assertions_test.exs | 22 ++++++++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/lib/elixir/lib/macro.ex b/lib/elixir/lib/macro.ex
index 6f9ff8dc7b5..4e106b74752 100644
--- a/lib/elixir/lib/macro.ex
+++ b/lib/elixir/lib/macro.ex
@@ -1832,13 +1832,13 @@ defmodule Macro do
   defp do_expand_once({:__DIR__, _, atom}, env) when is_atom(atom),
     do: {:filename.dirname(env.file), true}
 
-  defp do_expand_once({:__ENV__, _, atom}, env) when is_atom(atom) do
+  defp do_expand_once({:__ENV__, _, atom}, env) when is_atom(atom) and env.context != :match do
     env = update_in(env.versioned_vars, &maybe_escape_map/1)
     {maybe_escape_map(env), true}
   end
 
   defp do_expand_once({{:., _, [{:__ENV__, _, atom}, field]}, _, []} = original, env)
-       when is_atom(atom) and is_atom(field) do
+       when is_atom(atom) and is_atom(field) and env.context != :match do
     if Map.has_key?(env, field) do
       {maybe_escape_map(Map.get(env, field)), true}
     else
diff --git a/lib/elixir/test/elixir/macro_test.exs b/lib/elixir/test/elixir/macro_test.exs
index 15004ed8db9..9302e5df709 100644
--- a/lib/elixir/test/elixir/macro_test.exs
+++ b/lib/elixir/test/elixir/macro_test.exs
@@ -196,6 +196,16 @@ defmodule MacroTest do
       assert Code.eval_quoted(expanded) == {env.versioned_vars, []}
     end
 
+    test "env in :match context does not expand" do
+      env = %{__ENV__ | line: 0, lexical_tracker: self(), context: :match}
+
+      expanded = Macro.expand_once(quote(do: __ENV__), env)
+      assert expanded == quote(do: __ENV__)
+
+      expanded = Macro.expand_once(quote(do: __ENV__.file), env)
+      assert expanded == quote(do: __ENV__.file)
+    end
+
     defmacro local_macro(), do: raise("ignored")
 
     test "vars" do
diff --git a/lib/ex_unit/test/ex_unit/assertions_test.exs b/lib/ex_unit/test/ex_unit/assertions_test.exs
index cebf202288f..dcbf338afc8 100644
--- a/lib/ex_unit/test/ex_unit/assertions_test.exs
+++ b/lib/ex_unit/test/ex_unit/assertions_test.exs
@@ -256,6 +256,28 @@ defmodule ExUnit.AssertionsTest do
     end
   end
 
+  test "assert match with __ENV__ in the pattern" do
+    message =
+      ExUnit.CaptureIO.capture_io(:stderr, fn ->
+        assert_raise CompileError, fn ->
+          Code.eval_string("""
+          defmodule EnvMatch do
+            import ExUnit.Assertions
+
+            def run do
+              assert __ENV__ = %{}
+            end
+          end
+          """)
+        end
+      end)
+
+    assert message =~ "invalid pattern in match, __ENV__ is not allowed in matches"
+  after
+    :code.purge(EnvMatch)
+    :code.delete(EnvMatch)
+  end
+
   test "assert match?" do
     true = assert match?({2, 1}, Value.tuple())