show internal but not hidden config options, while still hiding test options (#84997)

(cherry picked from commit aab732cb82)

changelogs/fragments/config_priv.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - ansible-config will now show internal, but not test configuration entries. This allows for debugging but still denoting the configurations as internal use only (_ prefix).

lib/ansible/config/manager.py

@@ -480,9 +480,9 @@ class ConfigManager(object):
         else:
             ret = self._plugins.get(plugin_type, {}).get(name, {})
 
-        if ignore_private:
+        if ignore_private:  # ignore 'test' config entries, they should not change runtime behaviors
             for cdef in list(ret.keys()):
-                if cdef.startswith('_'):
+                if cdef.startswith('_Z_'):
                     del ret[cdef]
         return ret
 

test/integration/targets/ansible-config/tasks/main.yml

@@ -141,3 +141,17 @@
       when:
         - item[1] in gs[item[0]]
       loop: '{{gs_keys | product(gs_all) }}'
+
+- name: test ansible-config init for valid private and no hidden
+  vars:
+    config_keys: "{{ config_dump['stdout'] | from_json | selectattr('name', 'defined') }}"
+  block:
+    - name: run config full dump
+      shell: ansible-config dump -t all -f json
+      register: config_dump
+
+    - name: validate we get 'internal' but not hidden (_Z_)
+      assert:
+        that:
+          - config_keys | selectattr('name',  'match', '_.*') | length > 0
+          - config_keys | selectattr('name', 'match', '_Z_.*') | length == 0