_postgis_index_extent() crashes server

[robins]

Providing bogus inputs to _postgis_index_extent() crashes server.

$ psql
psql (13beta2, server 13.3)
Type "help" for help.

regression=> \x
Expanded display is on.

regression=> \dx postgis
List of installed extensions
-[ RECORD 1 ]--------------------------------------------------------------------
Name        | postgis
Version     | 3.0.3
Schema      | public
Description | PostGIS geometry, geography, and raster spatial types and functions

regression=> select public._postgis_index_extent(cast('-' as regclass), version()) as c3;
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!?> \q

[pramsey]

Milestone renamed

[robe]

In prep for 3.1.3 release

[robe]

Still crashes on pg14, backtrace gives me this:

Thread 1 received signal SIGSEGV, Segmentation fault.
[Switching to Thread 16088.0x4d28]
RelationGetIndexList (relation=relation@entry=0x0) at relcache.c:4584
4584            if (relation->rd_indexvalid)

[Paul Ramsey <pramsey@…>]

In 4481969/git:

Catch special "no oid" regclass before passing in to index search, references #4917

[Paul Ramsey <pramsey@…>]

In 4580ed1/git:

Catch special "no oid" regclass before passing in to index search, references #4917

[Paul Ramsey <pramsey@…>]

In 1ffd49d/git:

Catch special "no oid" regclass before passing in to index search, references #4917

[pramsey]

That's incredibly specifically obscure. Why would you ever do that?