From c69d45533518a8528e821f7eb5c643c22cd115de Mon Sep 17 00:00:00 2001
From: Thomas <1258170+ThomasSevestre@users.noreply.github.com>
Date: Tue, 2 Dec 2025 12:59:05 +0100
Subject: [PATCH] add support for nested as

---
 lib/sshkit/backends/abstract.rb     |  4 +--
 test/unit/backends/test_abstract.rb | 55 +++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/lib/sshkit/backends/abstract.rb b/lib/sshkit/backends/abstract.rb
index 592f7b08..62bf3ea1 100644
--- a/lib/sshkit/backends/abstract.rb
+++ b/lib/sshkit/backends/abstract.rb
@@ -103,6 +103,7 @@ def with(environment, &_block)
       end
 
       def as(who, &_block)
+        who_old = [@user, @group]
         if who.is_a? Hash
           @user  = who[:user]  || who["user"]
           @group = who[:group] || who["group"]
@@ -118,8 +119,7 @@ def as(who, &_block)
         EOTEST
         yield
       ensure
-        remove_instance_variable(:@user)
-        remove_instance_variable(:@group)
+        @user, @group = *who_old
       end
 
       class << self
diff --git a/test/unit/backends/test_abstract.rb b/test/unit/backends/test_abstract.rb
index e7afac83..1f2b33aa 100644
--- a/test/unit/backends/test_abstract.rb
+++ b/test/unit/backends/test_abstract.rb
@@ -111,6 +111,61 @@ def test_within_home
         assert_equal 'cd ~/foo && /usr/bin/env cat file', backend.executed_command.to_command
       end
 
+      def test_as_properly_clears
+        backend = ExampleBackend.new do
+          as :root do
+            execute :cat, 'file', :strip => false
+          end
+
+          execute :cat, 'file', :strip => false
+        end
+
+        backend.run
+
+        assert_equal '/usr/bin/env cat file', backend.executed_command.to_command
+      end
+
+      def test_as_root
+        backend = ExampleBackend.new do
+          as :root do
+            execute :cat, 'file', :strip => false
+          end
+        end
+
+        backend.run
+
+        assert_equal 'sudo -u root -- sh -c /usr/bin/env\\ cat\\ file', backend.executed_command.to_command
+      end
+
+      def test_nested_as
+        backend = ExampleBackend.new do
+          as :root do
+            as :other_user do
+              execute :cat, 'file', :strip => false
+            end
+          end
+        end
+
+        backend.run
+
+        assert_equal 'sudo -u other_user -- sh -c /usr/bin/env\\ cat\\ file', backend.executed_command.to_command
+      end
+
+      def test_nested_as_properly_clears
+        backend = ExampleBackend.new do
+          as :root do
+            as :other_user do
+              execute :cat, 'file', :strip => false
+            end
+            execute :cat, 'file', :strip => false
+          end
+        end
+
+        backend.run
+
+        assert_equal 'sudo -u root -- sh -c /usr/bin/env\\ cat\\ file', backend.executed_command.to_command
+      end
+
       def test_background_logs_deprecation_warnings
         deprecation_out = +''
         SSHKit.config.deprecation_output = deprecation_out