Improve duplicate list detection in password upgrade check

- Deduplicate listnames list before processing
- Track both listname and internal_name to catch all duplicate cases
- Use real_name for display instead of internal_name for better readability
- Add multiple levels of deduplication to ensure each list appears only once

This fixes an issue where the same list could appear multiple times in the
output with different email addresses.

Author: jared mauch

bin/update

@@ -683,24 +683,32 @@ def check_and_notify_password_upgrades(dry_run=False):
 
     print('Checking for lists with old password formats...')
     lists_needing_upgrade = []
-    seen_lists = {}  # Track by internal name to avoid duplicates
+    seen_listnames = set()  # Track by listname to avoid duplicates
+    seen_internal_names = set()  # Track by internal name to avoid duplicates
 
     # Check all lists for old password formats
-    listnames = Utils.list_names()
+    # Deduplicate listnames first to avoid processing the same list multiple times
+    listnames = list(dict.fromkeys(Utils.list_names()))  # Preserves order, removes duplicates
     for listname in listnames:
+        # Skip if we've already seen this listname
+        if listname in seen_listnames:
+            continue
+        seen_listnames.add(listname)
+        
         try:
             mlist = MailList.MailList(listname, lock=0)
         except Exception as e:
             print(C_('Warning: Could not check list %(listname)s: %(e)s') % {
             'listname': listname, 'e': e})
             continue
 
-        # Use internal_name() as key to avoid processing the same list twice
+        # Also check by internal_name() to catch cases where different listnames
+        # map to the same internal list
         internal_name = mlist.internal_name()
-        if internal_name in seen_lists:
-            # Already processed this list, skip
+        if internal_name in seen_internal_names:
+            # Already processed this list (by internal name), skip
             continue
-        seen_lists[internal_name] = True
+        seen_internal_names.add(internal_name)
 
         needs_upgrade = False
         # Check list admin password
@@ -738,8 +746,10 @@ def check_and_notify_password_upgrades(dry_run=False):
             print(C_('DRY-RUN: Would send password upgrade notifications to %(count)d list(s).') % {
                 'count': len(lists_needing_upgrade)})
             for mlist in lists_needing_upgrade:
+                # Use real_name for display, fallback to internal_name if real_name is not set
+                display_name = mlist.real_name or mlist.internal_name()
                 print(C_('  - Would notify owners of %(listname)s (%(listaddr)s)') % {
-                    'listname': mlist.internal_name(),
+                    'listname': display_name,
                     'listaddr': mlist.GetListEmail()})
         else:
             for mlist in lists_needing_upgrade: