apt: ignore fail_on_autoremove and allow_downgrade when using aptitude (#81445)

* apt: ignore fail_on_autoremove and allow_downgrade when using aptitude

* fail_on_autoremove (--no-remove) and allow_downgrade (--allow-downgrades)
  parameters are only valid for apt-get and not for aptitude. Ignore them when
  aptitude is detected and used.

Fixes: #77868

changelogs/fragments/apt_fail_on_autoremove.yml

@@ -0,0 +1,3 @@
+---
+bugfixes:
+  - apt - ignore fail_on_autoremove and allow_downgrade parameters when using aptitude (https://github.com/ansible/ansible/issues/77868).

lib/ansible/modules/apt.py

@@ -104,6 +104,7 @@ options:
       - This option enables the named package and version to replace an already installed higher version of that package.
       - Note that setting O(allow_downgrade=true) can make this module behave in a non-idempotent way.
       - (The task could end up with a set of packages that does not match the complete list of specified packages to install).
+      - 'O(allow_downgrade) is only supported by C(apt) and will be ignored if C(aptitude) is detected or specified.'
     aliases: [ allow-downgrade, allow_downgrades, allow-downgrades ]
     type: bool
     default: 'no'
@@ -171,7 +172,8 @@ options:
     description:
       - 'Corresponds to the C(--no-remove) option for C(apt).'
       - 'If V(true), it is ensured that no packages will be removed or the task will fail.'
-      - 'O(fail_on_autoremove) is only supported with O(state) except V(absent)'
+      - 'O(fail_on_autoremove) is only supported with O(state) except V(absent).'
+      - 'O(fail_on_autoremove) is only supported by C(apt) and will be ignored if C(aptitude) is detected or specified.'
     type: bool
     default: 'no'
     version_added: "2.11"
@@ -1091,13 +1093,24 @@ def upgrade(m, mode="yes", force=False, default_release=None,
         force_yes = ''
 
     if fail_on_autoremove:
-        fail_on_autoremove = '--no-remove'
+        if apt_cmd == APT_GET_CMD:
+            fail_on_autoremove = '--no-remove'
+        else:
+            m.warn("APTITUDE does not support '--no-remove', ignoring the 'fail_on_autoremove' parameter.")
+            fail_on_autoremove = ''
     else:
         fail_on_autoremove = ''
 
     allow_unauthenticated = '--allow-unauthenticated' if allow_unauthenticated else ''
 
-    allow_downgrade = '--allow-downgrades' if allow_downgrade else ''
+    if allow_downgrade:
+        if apt_cmd == APT_GET_CMD:
+            allow_downgrade = '--allow-downgrades'
+        else:
+            m.warn("APTITUDE does not support '--allow-downgrades', ignoring the 'allow_downgrade' parameter.")
+            allow_downgrade = ''
+    else:
+        allow_downgrade = ''
 
     if apt_cmd is None:
         if use_apt_get:

test/integration/targets/apt/tasks/repo.yml

@@ -400,6 +400,8 @@
         - { upgrade_type: safe, force_apt_get: True }
         - { upgrade_type: full, force_apt_get: True }
 
+    - include_tasks: "upgrade_scenarios.yml"
+
     - name: Remove aptitude if not originally present
       apt:
         pkg: aptitude

test/integration/targets/apt/tasks/upgrade_scenarios.yml

@@ -0,0 +1,25 @@
+# See https://github.com/ansible/ansible/issues/77868
+# fail_on_autoremove is not valid parameter for aptitude
+- name: Use fail_on_autoremove using aptitude
+  apt:
+    upgrade: yes
+    fail_on_autoremove: yes
+  register: fail_on_autoremove_result
+
+- name: Check if fail_on_autoremove does not fail with aptitude
+  assert:
+    that:
+    - not fail_on_autoremove_result.failed
+
+# See https://github.com/ansible/ansible/issues/77868
+# allow_downgrade is not valid parameter for aptitude
+- name: Use allow_downgrade using aptitude
+  apt:
+    upgrade: yes
+    allow_downgrade: yes
+  register: allow_downgrade_result
+
+- name: Check if allow_downgrade does not fail with aptitude
+  assert:
+    that:
+    - not allow_downgrade_result.failed