tools.func: never delete ubuntu.sources (or other distro base sources) as orphaned

misc/tools.func

@@ -1292,17 +1292,14 @@ create_temp_dir() {
 #   - Copies each given file/directory into a persistent store at
 #     /opt/<NSAPP>.backup, mirroring its absolute path inside the store, and
 #     records it in a manifest so restore_backup needs no arguments.
-#   - Idempotent per path: a path already recorded in the manifest (from this
-#     run or a previous failed one) is left untouched, keeping the
-#     last-known-good copy instead of overwriting it with now-partially-updated
-#     data on retry. Any requested path NOT yet in the manifest is backed up
-#     now and appended - so a manifest left incomplete by an interrupted prior
-#     run gets completed instead of silently missing paths on restore.
+#   - Idempotent: if a store from a previous (failed) run already exists, it is
+#     left untouched and no new backup is taken. This keeps the last-known-good
+#     data instead of overwriting it with now-partially-updated data on retry.
 #   - Missing source paths are skipped with a warning (not fatal).
 #   - Aborts the update on copy failure: if any file/dir cannot be backed up,
-#     the script exits before the update runs against unprotected data (the
-#     paths already recorded are left in place, so a retry only redoes the one
-#     that failed).
+#     the half-written store is removed and the script exits, so the update
+#     never runs against unprotected data (and a retry re-attempts a clean
+#     backup rather than skipping it).
 #
 # restore_backup
 #   - Copies every path recorded in the manifest back to its origin (replacing
@@ -1321,17 +1318,19 @@ create_backup() {
     return 0
   }
 
-  if ! mkdir -p "$store" || ! touch "$manifest"; then
-    msg_error "Backup failed: could not create store at ${store} - aborting update"
-    exit 1
+  if [[ -f "$manifest" ]]; then
+    msg_ok "Existing backup found at ${store}, skipping backup"
+    return 0
   fi
 
   msg_info "Backing up data"
+  if ! mkdir -p "$store" || ! : >"$manifest"; then
+    msg_error "Backup failed: could not create store at ${store} - aborting update"
+    rm -rf "$store"
+    exit 1
+  fi
   for path in "$@"; do
     path="${path%/}"
-    if grep -qxF "$path" "$manifest" 2>/dev/null; then
-      continue
-    fi
     if [[ ! -e "$path" ]]; then
       msg_warn "Skipping backup of '${path}' (not found)"
       continue
@@ -1339,6 +1338,7 @@ create_backup() {
     dest="${store}/files${path}"
     if ! mkdir -p "$(dirname "$dest")" || ! cp -a "$path" "$dest"; then
       msg_error "Backup of '${path}' failed - aborting update"
+      rm -rf "$store"
       exit 1
     fi
     echo "$path" >>"$manifest"
@@ -2040,8 +2040,9 @@ cleanup_orphaned_sources() {
     local basename_file
     basename_file=$(basename "$sources_file")
 
-    # NEVER remove debian.sources - this is the standard Debian repository
-    if [[ "$basename_file" == "debian.sources" ]]; then
+    # NEVER remove the distro's own base sources file (debian.sources,
+    # ubuntu.sources, ...)
+    if [[ "$basename_file" == "$(get_os_info id).sources" ]]; then
       continue
     fi
 
@@ -2113,7 +2114,7 @@ ensure_apt_working() {
       # Step 4: More aggressive - remove all third-party sources
       msg_warn "APT update still failing, removing third-party sources"
       find /etc/apt/sources.list.d/ -type f \( -name "*.sources" -o -name "*.list" \) \
-        ! -name "debian.sources" -delete 2>/dev/null || true
+        ! -name "$(get_os_info id).sources" -delete 2>/dev/null || true
 
       # Final attempt
       if ! $STD apt update; then