Multi-column gist index is displayed in wrong order

[ab-pm]

I'm using a multi-column GiST index exclusion constraint. It was created with a specific order of columns, however the "SQL" view on the table or constraint show them in the wrong order.

To Reproduce

CREATE EXTENSION IF NOT EXISTS btree_gist;
CREATE TABLE a_b_relation (
    a integer NOT NULL,
    b integer NOT NULL,
    valid tstzrange NOT NULL,
    CONSTRAINT a_b_excl EXCLUDE USING gist (
        a WITH =,
        b WITH =,
        valid WITH &&
    )
);

Then visit the "SQL" tab for the public.a_b_relation table. It'll show

CREATE TABLE IF NOT EXISTS public.a_b_relation
(
    a integer NOT NULL,
    b integer NOT NULL,
    valid tstzrange NOT NULL,
    CONSTRAINT a_b_excl EXCLUDE USING gist (
        valid WITH &&,
        b WITH =,
        a WITH =)

)

Similarly, the "SQL" view of the constraint itself has the same; and in the "Properties"->"Constraints"->"Exclude" dialog the "Columns/Expressions" table column also lists them in the wrong order.

Expected behavior

It should display the exclusion constraint with the rows in the same order they were created in. Notice that psql gets it right:

example=# \d a_b_relation 
             Table "public.a_b_relation"
 Column |   Type    | Collation | Nullable | Default 
--------+-----------+-----------+----------+---------
 a      | integer   |           | not null | 
 b      | integer   |           | not null | 
 valid  | tstzrange |           | not null | 
Indexes:
    "a_b_excl" EXCLUDE USING gist (a WITH =, b WITH =, valid WITH &&)

Environment:

• OS: Ubuntu
• Version: 8.14
• Mode: Desktop

Additional context

I found the thread bugfix: dlgIndex column order from 2009 on the mailing list which might be related, but I guess this is about ordering (ASC, DESC etc) in a column, not the order amongst columns.

[yogeshmahajan-1903]

Working fine.