Fix bug when using pinned variable in with else block (#13667)

Author: sabiwara

lib/elixir/src/elixir_erl_pass.erl

@@ -425,8 +425,8 @@ translate_with_else(Meta, [{'else', Else}], S) ->
   RaiseClause = {'->', Generated, [[RaiseVar], RaiseExpr]},
 
   Clauses = elixir_erl_clauses:get_clauses('else', [{'else', Else ++ [RaiseClause]}], match),
-  {TranslatedClauses, SC} = elixir_erl_clauses:clauses(Clauses, SV),
-  with_else_closure(Meta, TranslatedClauses, SC).
+  {TranslatedClauses, SC} = elixir_erl_clauses:clauses(Clauses, SV#elixir_erl{extra=pin_guard}),
+  with_else_closure(Meta, TranslatedClauses, SC#elixir_erl{extra=SV#elixir_erl.extra}).
 
 with_else_closure(Meta, TranslatedClauses, S) ->
   Ann = ?ann(Meta),

lib/elixir/test/elixir/kernel/with_test.exs

@@ -25,6 +25,30 @@ defmodule Kernel.WithTest do
     assert with({^key, res} <- ok(42), do: res) == 42
   end
 
+  test "pin matching with multiple else" do
+    key = :error
+
+    first_else =
+      with nil <- error() do
+        :ok
+      else
+        ^key -> :pinned
+        _other -> :other
+      end
+
+    assert first_else == :pinned
+
+    second_else =
+      with nil <- ok(42) do
+        :ok
+      else
+        ^key -> :pinned
+        _other -> :other
+      end
+
+    assert second_else == :other
+  end
+
   test "two levels with" do
     result =
       with {:ok, n1} <- ok(11),