RTC: Fix fallthrough for sync update switch statement by chriszarate · Pull Request #76060 · WordPress/gutenberg

chriszarate · 2026-03-02T22:42:20Z

What?

Fix a bug where the UPDATE_TYPE_COMPACTION case in the sync server's switch statement would fall through to the default case (WP_Error) when a newer compaction already existed.

Backport PR: WordPress/wordpress-develop#11118

Why?

When the sync server receives a compaction update but a newer compaction already exists, the code correctly skips it. But then it falls through to the default case via break, which returns a WP_Error for invalid sync update type.

In practice this is fairly harmless, but results in failed requests that could cause concern.

How?

Replace the break after the $has_newer_compaction check with return true, so the stale compaction is silently discarded instead of falling through.

Testing Instructions

This can be difficult to replicate, but:

Settings > Writing > Enable real-time collaboration.
Open a post in two browser tabs.
Make edits in both tabs to generate sync traffic.
Wait for compaction updates. Meanwhile, refresh the page periodically to increase the likelihood of stale compaction updates.
Verify that no sync update request returns 400.

github-actions · 2026-03-02T22:43:09Z

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Co-authored-by: chriszarate <czarate@git.wordpress.org>
Co-authored-by: maxschmeling <maxschmeling@git.wordpress.org>
Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

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github-actions · 2026-03-03T15:18:00Z

There was a conflict while trying to cherry-pick the commit to the wp/7.0 branch. Please resolve the conflict manually and create a PR to the wp/7.0 branch.

PRs to wp/7.0 are similar to PRs to trunk, but you should base your PR on the wp/7.0 branch instead of trunk.

# Checkout the wp/7.0 branch instead of trunk.
git checkout wp/7.0

# Create a new branch for your PR.
git checkout -b my-branch

# Cherry-pick the commit.
git cherry-pick 32824fa1dc8c0c91789b1def935037b304cfae30

# Check which files have conflicts.
git status

# Resolve the conflict...
# Add the resolved files to the staging area.
git status
git add .
git cherry-pick --continue

# Push the branch to the repository
git push origin my-branch

# Create a PR and set the base to the wp/7.0 branch.
# See https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/changing-the-base-branch-of-a-pull-request.

github-actions · 2026-03-03T15:26:14Z

There was a conflict while trying to cherry-pick the commit to the wp/7.0 branch. Please resolve the conflict manually and create a PR to the wp/7.0 branch.

PRs to wp/7.0 are similar to PRs to trunk, but you should base your PR on the wp/7.0 branch instead of trunk.

# Checkout the wp/7.0 branch instead of trunk.
git checkout wp/7.0

# Create a new branch for your PR.
git checkout -b my-branch

# Cherry-pick the commit.
git cherry-pick 32824fa1dc8c0c91789b1def935037b304cfae30

# Check which files have conflicts.
git status

# Resolve the conflict...
# Add the resolved files to the staging area.
git status
git add .
git cherry-pick --continue

# Push the branch to the repository
git push origin my-branch

# Create a PR and set the base to the wp/7.0 branch.
# See https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/changing-the-base-branch-of-a-pull-request.

* Fix fallthrough for sync update switch statement * Add PR to backport log Co-authored-by: chriszarate <czarate@git.wordpress.org> Co-authored-by: maxschmeling <maxschmeling@git.wordpress.org> Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

github-actions · 2026-03-03T15:36:17Z

I just cherry-picked this PR to the wp/7.0 branch to get it included in the next release: 8e060d4

* Fix fallthrough for sync update switch statement * Add PR to backport log Co-authored-by: chriszarate <czarate@git.wordpress.org> Co-authored-by: maxschmeling <maxschmeling@git.wordpress.org> Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

Co-authored-by: chriszarate <czarate@git.wordpress.org> Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

When a user sends a stale compaction update to WP_HTTP_Polling_Sync_Server, it falls through the switch statement and results in a rest_invalid_update_type error (bad request). This generally has no ill effect since the compaction request is rescinded on the next polling cycle, but it could cause confusion for users who are monitoring client-side requests or server logs. To fix, replace the break after the $has_newer_compaction check with return true so that the stale compaction is silently discarded instead of falling through. Covered by unit test. Developed in: #11118. Syncs: WordPress/gutenberg#76060. Fixes #64781. Props czarate, mindctrl. git-svn-id: https://develop.svn.wordpress.org/trunk@61839 602fd350-edb4-49c9-b593-d223f7449a82

When a user sends a stale compaction update to WP_HTTP_Polling_Sync_Server, it falls through the switch statement and results in a rest_invalid_update_type error (bad request). This generally has no ill effect since the compaction request is rescinded on the next polling cycle, but it could cause confusion for users who are monitoring client-side requests or server logs. To fix, replace the break after the $has_newer_compaction check with return true so that the stale compaction is silently discarded instead of falling through. Covered by unit test. Developed in: WordPress/wordpress-develop#11118. Syncs: WordPress/gutenberg#76060. Fixes #64781. Props czarate, mindctrl. Built from https://develop.svn.wordpress.org/trunk@61839 git-svn-id: http://core.svn.wordpress.org/trunk@61126 1a063a9b-81f0-0310-95a4-ce76da25c4cd

CI run: #11167. See #64595. --- I've included a log of the Gutenberg changes with the following command: git log --reverse --format="- %s" 022d8dd3d461f91b15c1f0410649d3ebb027207f..e499abfb843a43ac88455ca319220c5f181e1cf3 | sed 's|#$[0-9][0-9]*$|https://github.com/WordPress/gutenberg/pull/\1|g; /github\.com\/WordPress\/gutenberg\/pull/!d' | pbcopy - Add documentation for contentRole and listView block supports (WordPress/gutenberg#75903) - Interactivity Router: fix back and forward navigation after refresh (WordPress/gutenberg#75927) - Real-time collaboration: Fix disconnect dialog on navigate (WordPress/gutenberg#75886) - Real Time Collab: Throttle syncing for inactive tabs. (WordPress/gutenberg#75843) - Components: Specify line-height to avoid inheriting default values (WordPress/gutenberg#75880) - Pattern Editing: Fix sibling blocks to edited pattern not being disabled (WordPress/gutenberg#75994) - Sync connector PHP behavior with Core backport changes (WordPress/gutenberg#75968) - Connectors: Avoid manual string concatenation (WordPress/gutenberg#75997) - DataForm: fix field label for panel (should not be uppercase) (WordPress/gutenberg#75944) - Views: add support for more overrides (all developer-defined config) (WordPress/gutenberg#75971) - Use homeUrl instead of siteUrl for link badge evaluations (WordPress/gutenberg#75978) - DataViews: Right-align `integer` and `number` fields (WordPress/gutenberg#75917) - Navigation Link: Compare internal links by host instead of origin (WordPress/gutenberg#76015) - Fix: Skip scaled image sideload for images below big image threshold (WordPress/gutenberg#75990) - Client side media cherry pick for 7.0 (WordPress/gutenberg#75998) - Show transform dropdown previews on focus as well as hover (WordPress/gutenberg#75940) (WordPress/gutenberg#75992) - RTC: Fix syncing of emoji / surrogate pairs (WordPress/gutenberg#76049) - [Real-time Collaboration] Fix sync issue on refresh (WordPress/gutenberg#76017) - Real-time collaboration: Improve disconnect dialog (WordPress/gutenberg#75970) - DataViews: Fix filter toggle flickering when there are locked or primary filters (WordPress/gutenberg#75913) (WordPress/gutenberg#76068) - Connectors: Dynamically register providers from WP AI Client registry (WordPress/gutenberg#76014) - PHP-only Blocks: Reflect bound attribute values in inspector controls (WordPress/gutenberg#76040) - Fix: Set quality and strip metadata in client-side image resize (WordPress/gutenberg#76029) - RTC: Prevent duplicate poll cycles (WordPress/gutenberg#76059) - RTC: Fix stale CRDT document persisted on save (WordPress/gutenberg#75975) - RTC: Disable multiple collaborators if meta boxes are present (WordPress/gutenberg#75939) - Directly inject styles in overlay to make styles stay consistently mounted (WordPress/gutenberg#75700) - Real-time collaboration: Fix comment syncing on site editor (WordPress/gutenberg#75746) - Real-time Collaboration: Bug fix for CRDT user selection and add tests (WordPress/gutenberg#75075) - RTC: Updates from backport PR (WordPress/gutenberg#75711) - RTC: Fix undefined array_first() call in sync storage (WordPress/gutenberg#75869) - RTC: Fix fallthrough for sync update switch statement (WordPress/gutenberg#76060) - Real-time collaboration: Remove block client IDs from Awareness, fix "Show Template" view (WordPress/gutenberg#75590) - RTC: Add session activity notifications (WordPress/gutenberg#76065) - Prevent non-reproducible Sass/CSS builds. (WordPress/gutenberg#76098) - Block toolbar and context menu: hide pattern actions in Revisions UI (WordPress/gutenberg#76066) - Try enabling style variation transforms for blocks in contentOnly mode (WordPress/gutenberg#75761) - Block toolbar: hide styles dropdown in Revisions UI (WordPress/gutenberg#76119) - Image block: fix lightbox srcset size (WordPress/gutenberg#76092) - Fix writing flow navigation for annotation style, or any other block with border radius (WordPress/gutenberg#76072) - Image: Hide 'Set as featured image' for in-editor revisions (WordPress/gutenberg#76123) - Connectors: Gate unavailable install actions behind install capability (WordPress/gutenberg#75980) - build: Exclude experimental pages from Core builds (WordPress/gutenberg#76038) - HTML & Shortcode: Disable viewport visibility support (WordPress/gutenberg#76138) - RTC: Verify client ID to avoid awareness mutation (WordPress/gutenberg#76056) - wp-build: Do not remove Core's default script modules registration (WordPress/gutenberg#75705) - wp-build: Deregister script modules before re-registering (WordPress/gutenberg#75909) - Remove `! function_exists()` checks from PHP templates (WordPress/gutenberg#76062) - Connectors: Update page identifier to options-connectors (WordPress/gutenberg#76156) - Connectors: Align init hook priorities with Core overrides (WordPress/gutenberg#76161) - Icon Block: Clean up selectors config (WordPress/gutenberg#75786) - Icons: Fix incorrect icon slug (WordPress/gutenberg#76165) - RTC: Enable RTC by default (WordPress/gutenberg#75739) - Rename and visibility modals: gate shortcuts behind canEditBlock to prevent triggering in revisions UI (WordPress/gutenberg#76168) - Fix: Block style variations not rendering in Site Editor Patterns page (WordPress/gutenberg#76122) - Client-side media processing: only use media upload provider when not in preview mode (WordPress/gutenberg#76124) - Notes: Disable for in-editor revisions (WordPress/gutenberg#76180) - Core Data: Support reading revision data in useEntityProp (fixes footnotes in revisions UI) (WordPress/gutenberg#76106) - Client-side media processing: Try plumbing invalidation to the block-editor's mediaUpload onSuccess callback (WordPress/gutenberg#76173) - Connectors: Improve responsive layout on small screens (WordPress/gutenberg#76186) - Interactivity API: Fix router initialization race condition on Safari/Firefox (WordPress/gutenberg#76053) (WordPress/gutenberg#76191) - Interactivity: Fix crypto.randomUUID crash in non-secure contexts (WordPress/gutenberg#76151) git-svn-id: https://develop.svn.wordpress.org/trunk@61843 602fd350-edb4-49c9-b593-d223f7449a82

CI run: WordPress/wordpress-develop#11167. See #64595. --- I've included a log of the Gutenberg changes with the following command: git log --reverse --format="- %s" 022d8dd3d461f91b15c1f0410649d3ebb027207f..e499abfb843a43ac88455ca319220c5f181e1cf3 | sed 's|#$[0-9][0-9]*$|https://github.com/WordPress/gutenberg/pull/\1|g; /github\.com\/WordPress\/gutenberg\/pull/!d' | pbcopy - Add documentation for contentRole and listView block supports (WordPress/gutenberg#75903) - Interactivity Router: fix back and forward navigation after refresh (WordPress/gutenberg#75927) - Real-time collaboration: Fix disconnect dialog on navigate (WordPress/gutenberg#75886) - Real Time Collab: Throttle syncing for inactive tabs. (WordPress/gutenberg#75843) - Components: Specify line-height to avoid inheriting default values (WordPress/gutenberg#75880) - Pattern Editing: Fix sibling blocks to edited pattern not being disabled (WordPress/gutenberg#75994) - Sync connector PHP behavior with Core backport changes (WordPress/gutenberg#75968) - Connectors: Avoid manual string concatenation (WordPress/gutenberg#75997) - DataForm: fix field label for panel (should not be uppercase) (WordPress/gutenberg#75944) - Views: add support for more overrides (all developer-defined config) (WordPress/gutenberg#75971) - Use homeUrl instead of siteUrl for link badge evaluations (WordPress/gutenberg#75978) - DataViews: Right-align `integer` and `number` fields (WordPress/gutenberg#75917) - Navigation Link: Compare internal links by host instead of origin (WordPress/gutenberg#76015) - Fix: Skip scaled image sideload for images below big image threshold (WordPress/gutenberg#75990) - Client side media cherry pick for 7.0 (WordPress/gutenberg#75998) - Show transform dropdown previews on focus as well as hover (WordPress/gutenberg#75940) (WordPress/gutenberg#75992) - RTC: Fix syncing of emoji / surrogate pairs (WordPress/gutenberg#76049) - [Real-time Collaboration] Fix sync issue on refresh (WordPress/gutenberg#76017) - Real-time collaboration: Improve disconnect dialog (WordPress/gutenberg#75970) - DataViews: Fix filter toggle flickering when there are locked or primary filters (WordPress/gutenberg#75913) (WordPress/gutenberg#76068) - Connectors: Dynamically register providers from WP AI Client registry (WordPress/gutenberg#76014) - PHP-only Blocks: Reflect bound attribute values in inspector controls (WordPress/gutenberg#76040) - Fix: Set quality and strip metadata in client-side image resize (WordPress/gutenberg#76029) - RTC: Prevent duplicate poll cycles (WordPress/gutenberg#76059) - RTC: Fix stale CRDT document persisted on save (WordPress/gutenberg#75975) - RTC: Disable multiple collaborators if meta boxes are present (WordPress/gutenberg#75939) - Directly inject styles in overlay to make styles stay consistently mounted (WordPress/gutenberg#75700) - Real-time collaboration: Fix comment syncing on site editor (WordPress/gutenberg#75746) - Real-time Collaboration: Bug fix for CRDT user selection and add tests (WordPress/gutenberg#75075) - RTC: Updates from backport PR (WordPress/gutenberg#75711) - RTC: Fix undefined array_first() call in sync storage (WordPress/gutenberg#75869) - RTC: Fix fallthrough for sync update switch statement (WordPress/gutenberg#76060) - Real-time collaboration: Remove block client IDs from Awareness, fix "Show Template" view (WordPress/gutenberg#75590) - RTC: Add session activity notifications (WordPress/gutenberg#76065) - Prevent non-reproducible Sass/CSS builds. (WordPress/gutenberg#76098) - Block toolbar and context menu: hide pattern actions in Revisions UI (WordPress/gutenberg#76066) - Try enabling style variation transforms for blocks in contentOnly mode (WordPress/gutenberg#75761) - Block toolbar: hide styles dropdown in Revisions UI (WordPress/gutenberg#76119) - Image block: fix lightbox srcset size (WordPress/gutenberg#76092) - Fix writing flow navigation for annotation style, or any other block with border radius (WordPress/gutenberg#76072) - Image: Hide 'Set as featured image' for in-editor revisions (WordPress/gutenberg#76123) - Connectors: Gate unavailable install actions behind install capability (WordPress/gutenberg#75980) - build: Exclude experimental pages from Core builds (WordPress/gutenberg#76038) - HTML & Shortcode: Disable viewport visibility support (WordPress/gutenberg#76138) - RTC: Verify client ID to avoid awareness mutation (WordPress/gutenberg#76056) - wp-build: Do not remove Core's default script modules registration (WordPress/gutenberg#75705) - wp-build: Deregister script modules before re-registering (WordPress/gutenberg#75909) - Remove `! function_exists()` checks from PHP templates (WordPress/gutenberg#76062) - Connectors: Update page identifier to options-connectors (WordPress/gutenberg#76156) - Connectors: Align init hook priorities with Core overrides (WordPress/gutenberg#76161) - Icon Block: Clean up selectors config (WordPress/gutenberg#75786) - Icons: Fix incorrect icon slug (WordPress/gutenberg#76165) - RTC: Enable RTC by default (WordPress/gutenberg#75739) - Rename and visibility modals: gate shortcuts behind canEditBlock to prevent triggering in revisions UI (WordPress/gutenberg#76168) - Fix: Block style variations not rendering in Site Editor Patterns page (WordPress/gutenberg#76122) - Client-side media processing: only use media upload provider when not in preview mode (WordPress/gutenberg#76124) - Notes: Disable for in-editor revisions (WordPress/gutenberg#76180) - Core Data: Support reading revision data in useEntityProp (fixes footnotes in revisions UI) (WordPress/gutenberg#76106) - Client-side media processing: Try plumbing invalidation to the block-editor's mediaUpload onSuccess callback (WordPress/gutenberg#76173) - Connectors: Improve responsive layout on small screens (WordPress/gutenberg#76186) - Interactivity API: Fix router initialization race condition on Safari/Firefox (WordPress/gutenberg#76053) (WordPress/gutenberg#76191) - Interactivity: Fix crypto.randomUUID crash in non-secure contexts (WordPress/gutenberg#76151) Built from https://develop.svn.wordpress.org/trunk@61843 git-svn-id: http://core.svn.wordpress.org/trunk@61130 1a063a9b-81f0-0310-95a4-ce76da25c4cd

Fix fallthrough for sync update switch statement

5bfef45

chriszarate requested review from ingeniumed and maxschmeling March 2, 2026 22:42

chriszarate requested a review from spacedmonkey as a code owner March 2, 2026 22:42

chriszarate added [Type] Bug An existing feature does not function as intended [Feature] Real-time Collaboration Phase 3 of the Gutenberg roadmap around real-time collaboration labels Mar 2, 2026

Add PR to backport log

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chriszarate changed the title ~~Fix fallthrough for sync update switch statement~~ RTC: Fix fallthrough for sync update switch statement Mar 2, 2026

chriszarate added the Backport to WP 7.0 Beta/RC Pull request that needs to be backported to the WordPress major release that's currently in beta label Mar 2, 2026

maxschmeling approved these changes Mar 2, 2026

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chriszarate mentioned this pull request Mar 2, 2026

Real-time collaboration: Prevent fall-through in sync polling server WordPress/wordpress-develop#11118

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ingeniumed approved these changes Mar 3, 2026

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chriszarate merged commit 32824fa into trunk Mar 3, 2026
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chriszarate deleted the fix/sync-update-type-fallthrough branch March 3, 2026 15:16

github-actions bot mentioned this pull request Mar 3, 2026

PHP backports for WP 7.0 #74043

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github-actions bot added this to the Gutenberg 22.7 milestone Mar 3, 2026

chriszarate added Backport to WP 7.0 Beta/RC Pull request that needs to be backported to the WordPress major release that's currently in beta and removed Backport to WP 7.0 Beta/RC Pull request that needs to be backported to the WordPress major release that's currently in beta labels Mar 3, 2026

github-actions bot removed the Backport to WP 7.0 Beta/RC Pull request that needs to be backported to the WordPress major release that's currently in beta label Mar 3, 2026

github-actions bot added the Backported to WP Core Pull request that has been successfully merged into WP Core label Mar 3, 2026

chriszarate added a commit that referenced this pull request Mar 5, 2026

Fix backport changelog for #76060

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chriszarate mentioned this pull request Mar 5, 2026

RTC: Fix backport changelog for #76060 #76174

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chriszarate added a commit that referenced this pull request Mar 5, 2026

Fix backport changelog for #76060 (#76174)

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Co-authored-by: chriszarate <czarate@git.wordpress.org> Co-authored-by: ingeniumed <ingeniumed@git.wordpress.org>

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RTC: Fix fallthrough for sync update switch statement#76060

RTC: Fix fallthrough for sync update switch statement#76060
chriszarate merged 2 commits intotrunkfrom
fix/sync-update-type-fallthrough

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