|  | @@ -8,6 +8,43 @@ This document contains change notes for bugfix releases in
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				|  |  |  the 4.x series, please see :ref:`whatsnew-4.2` for
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				|  |  |  an overview of what's new in Celery 4.2.
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				|  |  |  
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				|  |  | +4.2.1
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				|  |  | +=====
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				|  |  | +:release-date: 2018-07-18 11:00 AM IST
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				|  |  | +:release-by: Omer Katz
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				|  |  | +
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				|  |  | +- **Result Backend**: Fix deserialization of exceptions that are present in the producer codebase but not in the consumer codebase.
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				|  |  | +
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				|  |  | +  Contributed by **John Arnold**
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				|  |  | +
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				|  |  | +- **Message Protocol Compatibility**: Fix error caused by an invalid (None) timelimit value in the message headers when migrating messages from 3.x to 4.x.
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				|  |  | +
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				|  |  | +  Contributed by **Robert Kopaczewski**
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				|  |  | +
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				|  |  | +- **Result Backend**: Fix serialization of exception arguments when exception arguments are not JSON serializable by default.
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				|  |  | +
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				|  |  | +  Contributed by **Tom Booth**
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				|  |  | +
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				|  |  | +- **Worker**: Fixed multiple issues with rate limited tasks
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				|  |  | +
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				|  |  | +  Maintain scheduling order.
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				|  |  | +  Fix possible scheduling of a :class:`celery.worker.request.Request` with the wrong :class:`kombu.utils.limits.TokenBucket` which could cause tasks' rate limit to behave incorrectly. 
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				|  |  | +  Fix possible duplicated execution of tasks that were rate limited or if ETA/Countdown was provided for them.
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				|  |  | +
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				|  |  | +  Contributed by :github_user:`ideascf`
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				|  |  | +
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				|  |  | +- **Worker**: Defensively handle invalid timelimit header values in requests.
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				|  |  | +
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				|  |  | +  Contributed by **Omer Katz**
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				|  |  | +
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				|  |  | +Documentation fixes:
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				|  |  | +
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				|  |  | +
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				|  |  | +    - **Matt Wiens**
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				|  |  | +    - **Seunghun Lee**
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				|  |  | +    - **Lewis M. Kabui**
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				|  |  | +    - **Prathamesh Salunkhe**
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				|  |  | +
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				|  |  |  4.2.0
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				|  |  |  =====
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				|  |  |  :release-date: 2018-06-10 21:30 PM IST
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