[wp-trac] [WordPress Trac] #63450: Race condition for transient with no expiration and object cache active

[WordPress Trac]

#63450: Race condition for transient with no expiration and object cache active
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 Reporter:  hugod         |       Owner:  (none)
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  6.9
Component:  Cache API     |     Version:
 Severity:  normal        |  Resolution:
 Keywords:  has-patch     |     Focuses:
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Comment (by logicrays):

 ### ✅ Solution for Ticket: *Race condition for transient with no
 expiration and object cache active*

 The root issue is that when a **persistent object cache is enabled**,
 transients **without expiration** are only stored in the cache and not
 reliably cleaned from the database (`wp_options`). This causes
 **inconsistent values** when the object cache is temporarily unavailable.

 ---

 ### 🔧 Solution (in 5–6 lines):

 To resolve this, ensure `delete_transient()` **always deletes from both**
 the object cache and the `wp_options` table, even if the transient has no
 expiration. Additionally, `set_transient()` should **synchronize the
 database value** if no expiration is set or if the object cache is
 unavailable. Core logic should include fallback checks and ensure
 consistency between cache and database, especially when the cache layer is
 unstable or offline. This prevents stale values from being loaded and
 avoids hard-to-debug behavior in dependent features like rewrite rules.

 Let me know if you'd like a patch example or test case for core.

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Ticket URL: <https://core.trac.wordpress.org/ticket/63450#comment:3>
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