Preserve original variables when using a loop (#59426)

Fixes #59414

lib/ansible/executor/task_executor.py

@@ -423,7 +423,7 @@ class TaskExecutor:
 
                 for plugin_type, plugin_name in iteritems(clear_plugins):
                     for var in C.config.get_plugin_vars(plugin_type, plugin_name):
-                        if var in task_vars:
+                        if var in task_vars and var not in self._job_vars:
                             del task_vars[var]
 
         self._task.no_log = no_log

test/integration/targets/loops/tasks/main.yml

@@ -344,3 +344,18 @@
     loop_var: "{{ loop_var_name }}"
   vars:
     loop_var_name: templated_loop_var_name
+
+# https://github.com/ansible/ansible/issues/59414
+- name: Test preserving original connection related vars
+  debug:
+    var: ansible_remote_tmp
+  vars:
+    ansible_remote_tmp: /tmp/test1
+  with_items:
+  - 1
+  - 2
+  register: loop_out
+
+- assert:
+    that:
+      - loop_out['results'][1]['ansible_remote_tmp'] == '/tmp/test1'