pgsql: Improve coding pattern in Parallel Append code.

Improve coding pattern in Parallel Append code.

The create_append_path code didn't consider that list_concat will
modify it's first argument leading to inconsistent traversal of
resulting list.  In practice, it won't lead to any user-visible bug
but changing it for making the code behave consistently.

Reported-by: Tom Lane
Author: Tom Lane
Reviewed-by: Amit Khandekar and Amit Kapila
Discussion: https://postgr.es/m/32365.1528994120@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/98d476a965eefb52af53f4fb55dbfead0ede9282

Modified Files
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src/backend/optimizer/util/pathnode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)