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Message-ID: <775ff3bf-01b3-4218-84c0-653b2add1a65@eisentraut.org>
Date: Wed, 25 Mar 2026 07:16:26 +0100
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Subject: Re: [PATCH] Fix wrong argument to SOFT_ERROR_OCCURRED in
 timestamptz_date
To: Jianghua Yang <yjhjstz@gmail.com>, pgsql-hackers@lists.postgresql.org
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 <CAAZLFmSGti716gWeY=DCZ9TTVOixnHZ4_4V4tDzoeE86D64vOA@mail.gmail.com>
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From: Peter Eisentraut <peter@eisentraut.org>
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 <CAAZLFmSGti716gWeY=DCZ9TTVOixnHZ4_4V4tDzoeE86D64vOA@mail.gmail.com>
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On 24.03.26 16:44, Jianghua Yang wrote:
>   Hi hackers,
> 
>    I found a small bug in commit e2f289e5b9b ("Make many cast functions 
> error safe").
> 
>    In timestamptz_date(), the SOFT_ERROR_OCCURRED() check mistakenly
>    uses fcinfo->args instead of fcinfo->context:
> 
>    result = timestamptz2date_safe(timestamp, fcinfo->context);
>    if (SOFT_ERROR_OCCURRED(fcinfo->args))   /* should be fcinfo->context */
>        PG_RETURN_NULL();
> 
>    fcinfo->args is a NullableDatum[] array, not a Node *. The
>    SOFT_ERROR_OCCURRED macro casts its argument to Node * and reads
>    the NodeTag field. When given fcinfo->args, it interprets the first
>    argument's Datum value (a TimestampTz) as a NodeTag, which will
>    almost never match T_ErrorSaveContext. This causes the soft error
>    check to always evaluate to false.
> 
>    As a result, when the timestamptz-to-date conversion encounters an
>    overflow in error-safe mode, the function returns a wrong date value
>    instead of the expected NULL.
> 
>    All three sibling functions modified in the same commit (date_timestamp,
>    timestamp_date, date_timestamptz) correctly use fcinfo->context.
>    This appears to be a copy-paste oversight.
> 
>    The fix is a one-line change: fcinfo->args → fcinfo->context.

committed the fix, thanks