BUG #14849: jsonb_build_object doesn't like VARIADIC calls very much

The following bug has been logged on the website:

Bug reference: 14849
Logged by: Marko Tiikkaja
Email address: marko(at)joh(dot)to
PostgreSQL version: 10.0
Operating system: Linux
Description:

Hi,

This query fails with an unreasonable error message:

=# SELECT jsonb_build_object(VARIADIC '{a,b}'::text[]);
ERROR: invalid number of arguments: object must be matched key value
pairs

jsonb_object(text[]) can be used instead in this case, so perhaps
jsonb_build_object() could simply point to that one if a variadic call like
this is made?