sub-expressions not wrapped by parentheses

[theosotr]

I have the following query (simplified for opening issue):

expr = (Value(1) + Model.column)
squared = (expr * expr)
Model.select(fn.sum(expr), fn.avg(squared)).objects()

peewee generates the SQL query below

SELECT sum(1 + "t1"."column"), avg(1 + "t1"."column" * 1 + "t1"."column") FROM "model" AS "t1"

Notably, the sub-expressions in avg(1 + "t1"."column" * 1 + "t1"."column") are not wrapped by parentheses as expected. That is

SELECT sum(1 + "t1"."column"), avg((1 + "t1"."column") * (1 + "t1"."column")) FROM "model" AS "t1"

[coleifer]

Thanks for reporting. This bug was caused by modifying an internal flag on the expression node without copying it first. This caused subsequent usages of that expression node to carry-over the flag when they shouldn't have.