fix(mobile): show already-loaded custom emoji in the iOS reactions sheet by brow · Pull Request #9150 · block/buzz

brow · 2026-11-05T22:45:13Z

On iOS, the reactions sheet (long-press a reaction pill) could show a custom emoji as truncated :shortcode: text, for example :eye…, even though the same emoji rendered as an image on the message pill a moment before.

The sheet is a native UIKit view that downloaded each custom emoji again with its own URLSession request and showed the shortcode label until that download finished, and for good when it failed. A shortcode is illegible in a chip that size.

Now:

Flutter keeps the encoded bytes of custom emoji it has downloaded (a bounded LRU: 512 KiB per emoji, 8 MiB total, rebuilt when the media auth scope changes so accounts never share bytes) and hands them to the sheet, which decodes them without a fetch. Emoji the timeline never loaded still download natively as before.
A custom emoji in the sheet never shows its shortcode: it stays blank while loading and shows the sparkles icon, matching the native emoji picker, if the image cannot load. Reaction pills in Flutter get the same sparkles fallback. Inline emoji in message text keep the shortcode fallback, where it reads as text. Avatars in the sheet keep their initial.

Before / after

Reactions sheet header and chips right after opening, on a message with two custom-emoji reactions (synthetic test channel, captured from a 30 fps screen recording).

Before (main)	After (this branch)

Validation

Added tests: the native sheet's payload carries the bytes the pill already downloaded; the combined reaction tray shows sparkles, not the shortcode, when a custom emoji fails to load (the existing alignment test previously asserted the shortcode).
Full mobile suite and just mobile-check pass; the iOS simulator build compiles.
Automated simulator run (iPhone 17 Pro, iOS 27, main vs this branch, signed in to a test community): channel list, opening a channel, the message action sheet, the emoji picker, and the reactions sheet on a message carrying two custom emoji I added plus a thumbs-up. On main the sheet's custom-emoji chips show truncated :qa-... shortcodes for a few frames before the images arrive; on this branch they render as images from the first frame (see Before / after). Limitations: the emoji images load fine over the network in this setup, so the failed-download sparkles fallback was covered by tests only, not seen in the app; a long press on the combined reaction tray opened the message menu in the simulator, a tap opened the sheet.

🤖 Generated with Claude Code

The native reactions sheet downloaded each custom emoji again with URLSession and showed the `:shortcode:` label until that download succeeded, keeping it when the download failed. So an emoji visible on the message pill could appear as truncated shortcode text in the sheet. Flutter now keeps the encoded bytes of custom emoji it has downloaded (a bounded LRU, rebuilt with the media auth scope) and passes them to the sheet, which decodes them without a fetch. A custom emoji in the sheet or a reaction pill never shows its shortcode: the sheet stays blank while loading, and both show sparkles if the image cannot load, like the native emoji picker. Co-authored-by: studio <dc2fc481343672df31a689840c09299972e704dac592e0da6f18486646a7ee3e@buzz.block.builderlab.xyz> Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Signed-off-by: Tom Brow <tomb@squareup.com>

brow · 2026-11-05T22:45:22Z

@codex review

chatgpt-codex-connector · 2026-11-05T22:45:41Z

Codex Review Summary: ✅ Completed

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📝 Code Review	✅ Completed 2026-11-08T21:49:45.966524Z	`9c0c3ca`	Draft marked ready

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chatgpt-codex-connector · 2026-11-05T22:48:54Z

+          if let decoded { self.show(decoded) } else { fallback() }
+        }
+      }
+      return


Fall back to the URL when cached decoding fails

When Flutter receives a transient malformed 2xx response, MediaImageProvider._loadAsync invokes onBytesLoaded before attempting its own decode, so these bytes are cached even though the pill displays its error state. This branch treats those bytes as authoritative: if native decoding fails it shows sparkles and returns without trying the URL, whereas the previous sheet implementation could make a fresh request and recover after the server response was fixed. Continue through the existing URL-loading path when cached-byte decoding returns nil.

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chatgpt-codex-connector · 2026-11-05T22:48:54Z

+    if let bytes = data["bytes"] as? FlutterStandardTypedData {
+      DispatchQueue.global(qos: .userInitiated).async { [weak self] in
+        let decoded = NativeMessageImageLoader.decode(bytes.data)


Deduplicate cached-byte decoding across glyphs

When a custom-emoji reaction has multiple visible reactors, the filter glyph and every reactor-row glyph receive the same encoded bytes, but each independently submits a full animated-image decode to the global queue. Rapidly scrolling a large reactor list can therefore enqueue many uncancelled duplicate decodes, bypassing the four-operation admission limit and decoded-image cache used by NativeMessageImageLoader; route cached bytes through a shared URL-keyed, bounded decoder/cache instead.

AGENTS.md reference: AGENTS.md:L249-L257

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[P2] Share decoded images across cached-byte glyphs

This also repeats during profile hydration: updateProfiles reloads visible rows, each row creates a fresh glyph, and each glyph decodes the same animation again. Could cached bytes use the shared decoded-image cache and admission limit, rather than dispatching a decode per glyph?

Posted by Codex (gpt-6.1-sol) on behalf of kylez

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chatgpt-codex-connector · 2026-11-08T21:49:43Z

      filterQuality: FilterQuality.medium,
      semanticLabel: ':$shortcode:',
-      errorBuilder: (_, _, _) => Text(':$shortcode:', style: fallbackStyle),
+      onBytesLoaded: (bytes) => bytesCache.remember(url, bytes),


Forward bytes that arrive after opening the sheet

When the sheet is opened while the pill's image request is still in flight, reactionData() snapshots a cache miss and UIKit starts its own request; this callback may then populate the cache, but the cache is non-reactive and updateReactions() only runs when the reaction list changes. If the Flutter request subsequently succeeds while UIKit's separate request fails, the pill displays the emoji but the open sheet remains on sparkles. Notify the active sheet when cached bytes arrive, or otherwise share the in-flight load.

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github-actions · 2026-11-08T21:50:07Z

🔐 Codex Security Review

Note: This is an automated, security-focused review generated by Codex.
Use it as a supplement to human review; false positives are possible.

Scope

Exact PR diff: 8cce12f591988f29cc2beab5ff0c89d51862f31b...e47b32c07b22d6ade16464a0ff6e8ab2ad28e675

Model: gpt-6.1-sol

💡 Click "edited" above to see earlier reviews for this PR.

Review Summary

Overall Risk: MEDIUM

The cached emoji path introduces resource amplification that can exhaust iOS client memory.

Findings

[MEDIUM] `Deduplicate and bound decoding of cached emoji bytes`

Category: Reliability
Location: mobile/ios/Runner/NativeReactionDetails.swift:398 (source)
Description: Every byte-backed glyph now starts an independent decode, bypassing NativeMessageImageLoader's request deduplication, decoded-image cache, admission limit, and cancellation. A member can submit many distinct reaction shortcodes pointing to the same animated image; reaction uniqueness includes the shortcode, and timeline aggregation preserves these groups. Flutter shares the image and caches its bytes, but opening the native sheet creates every filter eagerly and decodes a separate image for each alias. A cached animation below 512 KiB can expand to roughly 3 MiB across 60 frames, so hundreds of aliases can retain around a gigabyte of duplicate decoded images.
Impact: Opening an affected reaction sheet can stall or terminate the iOS client through memory exhaustion.
Recommendation: Route cached bytes through a shared, bounded decoding path keyed by URL and auth scope, with cancellation and decoded-image reuse. Also deduplicate encoded bytes in the platform payload.

Notes

Validation was limited to read-only source inspection; builds and tests were not run.

_{Generated by Codex Security Review |

Requested by: @brow |

Workflow run}

tlongwell-block · 2026-11-09T04:12:36Z

🤖 Meli, Tyler’s AI agent, posting on his explicit behalf.

The remaining gap is verification of the transient fetch boundary. Both main and PR render the loaded custom-emoji pill and native reactions sheet successfully in the online happy path, so those captures do not demonstrate the reported failure or its fix. Please exercise opening the sheet after the pill has loaded while a subsequent fetch fails, and show that the retained bytes still render the emoji. The full mobile suite passed; no new production defect is established by this verification gap.

Reviewed head: e47b32c07b22d6ade16464a0ff6e8ab2ad28e675.

kazemek21

Kyle reviewed this PR and the Nexus review-tracker notes. Approved with the non-blocking cached-byte decoding feedback in the existing thread.

Posted by Codex (gpt-6.1-sol) on behalf of kylez

…ction-p * origin/main: (111 commits) feat(mobile): tag the reacted-to message author on reactions (#9141) fix(mobile): steady New DM picker rows and animate picks (#9249) perf(mobile): keep remote images on disk and show small ones as thumbnails (#9158) fix(relay): deliver slow cross-node events late instead of closing their recipients (#9235) fix(mobile): read only shown events from filtered Activity rows (#9215) fix(mobile): show the channel name as the notification subtitle (#9173) fix(mobile): keep Home's header clean under sheets (#9152) fix(mobile): show already-loaded custom emoji in the iOS reactions sheet (#9150) mobile: add follow and remind actions to inbox row menu (#9142) fix(mobile): start no threads in Solo chats (#9123) mobile: persist user profiles so names and avatars render on launch (#9116) fix(mobile): keep a sent thread reply above the composer (#9026) [buzz] Recover database pool capacity after stalled connections (#9267) feat: send a User-Agent on relay WebSocket upgrades (#9246) Record why relay connections close and quiet close warnings (#9245) fix(relay): say "channel owner or admin" in the call_webhook save refusal (#9169) feat(mobile): consolidate Solo chat settings in one sheet (#9255) fix(cli): preserve attachments across successive edits (#9226) fix(mobile): swipe left to reply so swipe-back keeps rightward drags (#9127) mobile: long-press a message link for open, copy and share (#9135) ... Signed-off-by: Matthew Boston <mboston@squareup.com>

…-profile * origin/main: (307 commits) fix: inline ARM64 atomics in Sprig image build (#9291) fix(mobile): show observed thread replies in Activity (#9286) Enable mobile huddles with Codex agents (#9269) fix(mobile): read mentions taller than the screen (#9243) test(relay): give every media e2e upload its own blob hash (#9272) Add invite preview video and fallback poster (#9282) NEXUS-4336: Wait for desktop-provider socket ownership proof (#9270) fix: unblock image audit with patched MCP SDK (#9287) feat(ci): allow admin dispatch of desktop candidate validation (#9288) feat(mobile): tag the reacted-to message author on reactions (#9141) fix(mobile): steady New DM picker rows and animate picks (#9249) perf(mobile): keep remote images on disk and show small ones as thumbnails (#9158) fix(relay): deliver slow cross-node events late instead of closing their recipients (#9235) fix(mobile): read only shown events from filtered Activity rows (#9215) fix(mobile): show the channel name as the notification subtitle (#9173) fix(mobile): keep Home's header clean under sheets (#9152) fix(mobile): show already-loaded custom emoji in the iOS reactions sheet (#9150) mobile: add follow and remind actions to inbox row menu (#9142) fix(mobile): start no threads in Solo chats (#9123) mobile: persist user profiles so names and avatars render on launch (#9116) ... Signed-off-by: Franco Sola <fsola@squareup.com> # Conflicts: # docs/nips/NIP-FA.md # docs/nips/NIP-FI.md

…e-mode * origin/main: (36 commits) feat(relay): let an operator mint invites for a community owner or admin (#9265) fix: inline ARM64 atomics in Sprig image build (#9291) fix(mobile): show observed thread replies in Activity (#9286) Enable mobile huddles with Codex agents (#9269) fix(mobile): read mentions taller than the screen (#9243) test(relay): give every media e2e upload its own blob hash (#9272) Add invite preview video and fallback poster (#9282) NEXUS-4336: Wait for desktop-provider socket ownership proof (#9270) fix: unblock image audit with patched MCP SDK (#9287) feat(ci): allow admin dispatch of desktop candidate validation (#9288) feat(mobile): tag the reacted-to message author on reactions (#9141) fix(mobile): steady New DM picker rows and animate picks (#9249) perf(mobile): keep remote images on disk and show small ones as thumbnails (#9158) fix(relay): deliver slow cross-node events late instead of closing their recipients (#9235) fix(mobile): read only shown events from filtered Activity rows (#9215) fix(mobile): show the channel name as the notification subtitle (#9173) fix(mobile): keep Home's header clean under sheets (#9152) fix(mobile): show already-loaded custom emoji in the iOS reactions sheet (#9150) mobile: add follow and remind actions to inbox row menu (#9142) fix(mobile): start no threads in Solo chats (#9123) ... Signed-off-by: Will Pfleger <wpfleger@block.xyz>

chatgpt-codex-connector Bot reviewed Nov 5, 2026

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brow marked this pull request as ready for review November 8, 2026 21:47

brow requested a review from a team as a code owner November 8, 2026 21:47

brow temporarily deployed to codex-review November 8, 2026 21:47 — with GitHub Actions Inactive

chatgpt-codex-connector Bot reviewed Nov 8, 2026

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github-actions Bot added the codex-security-review-current The posted Codex security review matches its recorded range. label Nov 8, 2026

Merge branch 'main' into reactions-sheet-custom-emoji

e47b32c

github-actions Bot removed the codex-security-review-current The posted Codex security review matches its recorded range. label Nov 8, 2026

brow temporarily deployed to codex-review November 8, 2026 22:44 — with GitHub Actions Inactive

github-actions Bot added the codex-security-review-current The posted Codex security review matches its recorded range. label Nov 8, 2026

kazemek21 approved these changes Nov 9, 2026

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brow merged commit ac2c583 into main Nov 9, 2026
53 checks passed

brow deleted the reactions-sheet-custom-emoji branch November 9, 2026 14:59

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fix(mobile): show already-loaded custom emoji in the iOS reactions sheet - #9150

fix(mobile): show already-loaded custom emoji in the iOS reactions sheet#9150
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[MEDIUM] Deduplicate and bound decoding of cached emoji bytes

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[MEDIUM] `Deduplicate and bound decoding of cached emoji bytes`