From: Tom Lane <tgl@sss.pgh.pa.us>
To: jacques@quantsolutions.co.za
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18456: Trigger data in plpython3u trigger-function changes
 in AFTER UPDATE OR INSERT trigger
In-reply-to: <18456-82d3d70134aefd28@postgresql.org>
References: <18456-82d3d70134aefd28@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
	message dated "Fri, 03 May 2024 14:37:12 -0000"
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Date: Sat, 04 May 2024 14:34:40 -0400
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PG Bug reporting form <noreply@postgresql.org> writes:
> Then the trigger data changes after the insert statement in the trigger
> function.

Hmm.  TD is defined as a global dictionary like SD, so it saves values
across calls to the plpython function.  So the inner INSERT operation
fires the same trigger, which decides not to print anything, but
nonetheless it's changed TD and the outer trigger call will see that.

There used to be similar problems in plain plpython functions if they
were invoked recursively, because named function arguments are also
passed as global variables.  We fixed that in a rather hacky way in
1d2fe56e4, ie save and restore those globals when recursing.
Probably the same thing could be done with TD.

			regards, tom lane