fix: detect view-once media on stanza 1 for linked devices + fix mediatype in enc node

[rsalcara]

Problem

Two bugs affecting view-once media (image/video/audio) on linked devices:

Bug 1 — decode-wa-message.ts

When a view-once message arrives at a linked device, the server sends two stanzas:

• Stanza 1 (enc): full media metadata — viewOnceMessage > imageMessage/videoMessage/audioMessage { viewOnce: true, mediaKey, directPath, ... }
• Stanza 2 (unavailable type="view_once"): fanout placeholder (already handled at line 294)

Stanza 1 was decoded but key.isViewOnce was never set, making it indistinguishable from regular media in messages.upsert. Consumers had no way to know the message was view-once.

Bug 2 — messages-send.ts

getMediaType() checks message.imageMessage, message.videoMessage, etc. directly. When viewOnce: true is set, generateWAMessageContent wraps the media inside viewOnceMessage.message, so message.imageMessage is undefined at the top level.

Result: mediatype attribute was missing from the enc node for all view-once media. WA servers silently dropped view-once video and audio messages (images were more lenient). Verified on production: image view-once arrived, video/audio did not — until this fix.

Fix

src/Utils/decode-wa-message.ts (+17 lines)
After decoding proto.Message, inspect viewOnceMessage / viewOnceMessageV2 / viewOnceMessageV2Extension wrappers for inner media with viewOnce: true. If found, set fullMessage.key.isViewOnce = true.

The viewOnceMessage wrapper is also used for interactive messages (carousel, buttons, lists) which carry interactiveMessage / listMessage inside — never imageMessage.viewOnce = true. The check is unambiguous.

src/Socket/messages-send.ts (+9 lines)
Before checking media fields in getMediaType(), unwrap viewOnceMessage / viewOnceMessageV2 / viewOnceMessageV2Extension recursively (same pattern as normalizeMessageContent). This ensures mediatype="image"/"video"/"audio" is correctly set on the enc node.

Testing

Verified on production (2026-03-20):

• ✅ Image view-once: received with key.isViewOnce = true, mediatype="image" on enc
• ✅ Video view-once: received and delivered (was silently dropped before fix)
• ✅ Audio view-once: received and delivered
• ✅ Interactive messages (carousel/buttons/lists): unaffected — viewOnceMessage wrapper with interactiveMessage inside is correctly not flagged as view-once media

Checklist

• Only touches decode-wa-message.ts and messages-send.ts
• No breaking changes
• Backwards compatible (interactive messages unchanged)
• Branch based on WhiskeySockets/Baileys master (not fork-specific commits)

[whiskeysockets-bot]

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[Copilot]

Pull request overview

Fixes two linked-device view-once media bugs by correctly (1) marking incoming stanza-1 view-once media as view-once, and (2) ensuring outgoing view-once media sets the correct mediatype attribute on the enc node so servers don’t drop it.

Changes:

• Detect view-once media in stanza 1 by inspecting view-once wrappers and setting fullMessage.key.isViewOnce = true during decryption.
• Fix getMediaType() to unwrap view-once wrappers before checking message media fields, restoring mediatype="image"/"video"/"audio" for view-once sends.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Utils/decode-wa-message.ts	Sets key.isViewOnce for linked-device stanza-1 view-once media by inspecting view-once wrappers’ inner media flags.
src/Socket/messages-send.ts	Unwraps view-once wrappers in getMediaType() so enc node mediatype is populated for view-once media.

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[Salientekill]

I'm almost certain they'll ask you to split that PR into two, one for each fix.

[rsalcara]

Thanks for the feedback! 🙌