BSDTimezone: distinguish UTC and Etc/UTC (#41234)

* Fixed BSDTimezone to distinguish UTC and Etc/UTC

* Added test for timezone to disinguish UTC vs Etc/UTC

lib/ansible/modules/system/timezone.py

@@ -705,25 +705,6 @@ class BSDTimezone(Timezone):
             return 'UTC'
 
         # Strategy 2:
-        #   Return planned timezone as current timezone if their content matches.
-        #   This is bad design to see `self.value` here,
-        #   but it's intended to avoid useless diff.
-        planned = self.value['name']['planned']
-        try:
-            planned_zonefile = os.path.join(zoneinfo_dir, planned)
-            already_planned_state = filecmp.cmp(planned_zonefile, localtime_file)
-
-        except OSError:
-            # Even if reading planned zoneinfo file gives an OSError, don't abort here,
-            # because a bit more detailed check will be done in `set`.
-            already_planned_state = False
-        # Handle the case where the file comp previously would claim UTC and Etc/UTC
-        # are the same because they are the same file, but not the same path. This
-        # breaks idempotent task runs.
-        if already_planned_state and (planned_zonefile == os.path.realpath(planned_zonefile)):
-            return planned
-
-        # Strategy 3:
         #   Follow symlink of /etc/localtime
         zoneinfo_file = localtime_file
         while not zoneinfo_file.startswith(zoneinfo_dir):
@@ -735,15 +716,16 @@ class BSDTimezone(Timezone):
         else:
             return zoneinfo_file.replace(zoneinfo_dir, '')
 
-        # Strategy 4:
-        #   Check all files in /usr/share/zoneinfo and return first match.
-        for dname, _, fnames in os.walk(zoneinfo_dir):
-            for fname in fnames:
+        # Strategy 3:
+        #   (If /etc/localtime is not symlinked)
+        #   Check all files in /usr/share/zoneinfo and return first non-link match.
+        for dname, _, fnames in sorted(os.walk(zoneinfo_dir)):
+            for fname in sorted(fnames):
                 zoneinfo_file = os.path.join(dname, fname)
-                if filecmp.cmp(zoneinfo_file, localtime_file):
+                if not os.path.islink(zoneinfo_file) and filecmp.cmp(zoneinfo_file, localtime_file):
                     return zoneinfo_file.replace(zoneinfo_dir, '')
 
-        # Strategy 5:
+        # Strategy 4:
         #   As a fall-back, return 'UTC' as default assumption.
         self.module.warn('Could not identify timezone name from /etc/localtime. Assuming UTC.')
         return 'UTC'

test/integration/targets/timezone/tasks/test.yml

@@ -81,6 +81,54 @@
     that:
       - not timezone_again_checkmode.changed
 
+##
+## tests for same timezones with different names
+##
+
+- name: check dpkg-reconfigure
+  shell: type dpkg-reconfigure
+  register: check_dpkg_reconfigure
+  ignore_errors: yes
+  changed_when: no
+
+- name: check timedatectl
+  shell: type timedatectl && timedatectl
+  register: check_timedatectl
+  ignore_errors: yes
+  changed_when: no
+
+- block:
+    - name: set timezone to Etc/UTC
+      timezone:
+        name: Etc/UTC
+
+    - name: change timezone from Etc/UTC to UTC
+      timezone:
+        name: UTC
+      register: timezone_etcutc_to_utc
+
+    - name: check timezone changed from Etc/UTC to UTC
+      assert:
+        that:
+          - timezone_etcutc_to_utc.changed
+          - timezone_etcutc_to_utc.diff.before.name == 'Etc/UTC'
+          - timezone_etcutc_to_utc.diff.after.name == 'UTC'
+
+    - name: change timezone from UTC to Etc/UTC
+      timezone:
+        name: Etc/UTC
+      register: timezone_utc_to_etcutc
+
+    - name: check timezone changed from UTC to Etc/UTC
+      assert:
+        that:
+          - timezone_utc_to_etcutc.changed
+          - timezone_utc_to_etcutc.diff.before.name == 'UTC'
+          - timezone_utc_to_etcutc.diff.after.name == 'Etc/UTC'
+
+  when:
+    # FIXME: Due to the bug of the dpkg-reconfigure, those tests failed on non-systemd debian
+    - check_dpkg_reconfigure.rc != 0 or check_timedatectl.rc == 0
 
 ##
 ## no systemd tests for timezone