openclaw - 💡(How to fix) Fix [Bug]: Zalo (zalouser) delivers document media twice for a single MEDIA: directive (images unaffected)

Summary

On the Zalo personal (zalouser) channel, when an assistant reply contains a single MEDIA: directive pointing to a document (e.g. .xlsx), the file is delivered twice as two separate attachment messages in the same turn. Images sent the same way appear only once.

The agent is behaving correctly — the outbound message contains exactly one MEDIA: directive (verified in the session *.jsonl). The duplication happens entirely in the delivery pipeline, and only for non-image media.

Environment

• OpenClaw 2026.5.19 (native systemd, built from source)
• Channel: zalouser (zca-js), group chat
• Node 22

Reproduction

1. Have an agent on the zalouser channel produce a reply whose text ends with a single directive, e.g.:

   Here is the file:
   
   MEDIA:/root/.openclaw/workspace-5am/finance/quy-nhom-5am.xlsx

2. Observe the Zalo chat: the .xlsx is delivered as two identical file messages (file → text → file in one turn).
3. Repeat with an image path (.png/.jpg) → delivered once (correct).

What I verified

• The session transcript shows exactly one MEDIA: token in the final assistant message (not two, no separate send tool call). So this is not the model re-echoing the path.
• Setting agents.defaults.blockStreamingDefault: "off" did not help — documents are still doubled. (channels.zalouser rejects a per-channel blockStreaming key: "must NOT have additional properties".)

Hypothesis

Likely the same dual-path reply-media normalization described in #68056 — media flows through both the block-reply path (onBlockReply / sendDirectBlockReply) and the final normalizeReplyPayloadMedia, whose persistedMediaBySource caches are not shared, so the same source is persisted/sent twice. The WhatsApp fix (#68111) does not appear to cover the zalouser document path. Images are unaffected because they take a single inline/render path.

Expected

A single MEDIA: directive should produce exactly one delivered attachment on zalouser, for documents as well as images.

Related

#68056, #68111, #17991, #42681