Re: remaining sql/json patches

Hi. small issues I found...

typo:
+-- Test mutabilily od query functions

+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("only datetime, bool, numeric, and text types can be casted
to jsonpath types")));

transformJsonPassingArgs's function: transformJsonValueExpr will make
the above code unreached.
also based on the `switch (typid)` cases,
I guess best message would be
errmsg("only datetime, bool, numeric, text, json, jsonb types can be
casted to jsonpath types")));

+ case JSON_QUERY_OP:
+ jsexpr->wrapper = func->wrapper;
+ jsexpr->omit_quotes = (func->quotes == JS_QUOTES_OMIT);
+
+ if (!OidIsValid(jsexpr->returning->typid))
+ {
+ JsonReturning *ret = jsexpr->returning;
+
+ ret->typid = JsonFuncExprDefaultReturnType(jsexpr);
+ ret->typmod = -1;
+ }
+ jsexpr->result_coercion = coerceJsonFuncExprOutput(pstate, jsexpr);

I noticed, if (!OidIsValid(jsexpr->returning->typid)) is the true
function JsonFuncExprDefaultReturnType may be called twice, not sure
if it's good or not..