fix tikv listing due to expired entries (#7115)

* fix tikv listing due to expired entries

When there are many entries with empty fileName values (which can happen after TTL cleanup), the continue statements prevent the loop counter from incrementing, creating an infinite loop.

* address comments

* Update weed/filer/tikv/tikv_store.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* address comments

Update weed/filer/tikv/tikv_store.go

Co-Authored-By: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

weed/filer/tikv/tikv_store.go

@@ -228,19 +228,31 @@ func (store *TikvStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPat
 			return err
 		}
 		defer iter.Close()
-		for i := int64(0); i < limit && iter.Valid(); i++ {
+		i := int64(0)
+		for iter.Valid() {
 			key := iter.Key()
 			if !bytes.HasPrefix(key, directoryPrefix) {
 				break
 			}
 			fileName := getNameFromKey(key)
-			if fileName == "" || fileName == startFileName && !includeStartFile {
+			if fileName == "" {
 				if err := iter.Next(); err != nil {
 					break
-				} else {
+				}
+				continue
+			}
+			if fileName == startFileName && !includeStartFile {
+				if err := iter.Next(); err != nil {
+					break
+				}
 				continue
 			}
+
+			// Check limit only before processing valid entries
+			if limit > 0 && i >= limit {
+				break
 			}
+
 			lastFileName = fileName
 			entry := &filer.Entry{
 				FullPath: util.NewFullPath(string(dirPath), fileName),
@@ -252,11 +264,15 @@ func (store *TikvStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPat
 				glog.V(0).InfofCtx(ctx, "list %s : %v", entry.FullPath, err)
 				break
 			}
+
+			// Only increment counter after successful processing
+			i++
+
 			if err := iter.Next(); !eachEntryFunc(entry) || err != nil {
 				break
 			}
 		}
-		return nil
+		return err
 	})
 	if err != nil {
 		return lastFileName, fmt.Errorf("prefix list %s : %v", dirPath, err)