Assertion failing in master, predicate.c - Mailing list pgsql-hackers

Hackers,

I stumbled upon an assertion while testing master for possible
bugs.  I am reporting it here in the hope that this report will
be useful.  The attached small regression test patch consistently
triggers an assert in predicate.c:

   TRAP: FailedAssertion("!isCommit || 
SxactIsPrepared(MySerializableXact)", File: "predicate.c", Line: 3372)

I originally hit this from sources with less than recent
code checked out, but the error is the same in a recent,
fresh `git clone` (4a0aab14dcb35550b55e623a3c194442c5666084)
The problem does not reproduce for me in REL_12_STABLE, though the
same assertion does exist in that branch.

I built on my laptop:

   Linux 4.19.0-5-amd64 #1 SMP Debian 4.19.37-3 (2019-05-15) x86_64 
GNU/Linux

I built using

   `./configure --enable-cassert --enable-tap-tests --with-perl 
--with-python --with-tcl`

The perl, python, and tcl options don't appear to matter, as nothing
changes using

   `./configure --enable-cassert && make -j4 && make check-world`

-- 
Mark Dilger