BUG #17334: Assert failed inside computeDistance() on gist index scanning

The following bug has been logged on the website:

Bug reference:      17334
Logged by:          Alexander Lakhin
Email address:      exclusion@gmail.com
PostgreSQL version: 14.1
Operating system:   Ubuntu 20.04
Description:

When executing the following queries:
CREATE TABLE point_tbl(f1 point);
CREATE INDEX gpointind ON point_tbl USING gist(f1);
INSERT INTO point_tbl SELECT ('0,0') FROM generate_series(1, 185);
INSERT INTO point_tbl VALUES ('0,NaN');
SET enable_seqscan=off; SELECT f1 <-> point '(0,0)' AS dist FROM point_tbl
ORDER BY dist;

I get a failed assertion with the backtrace:
Core was generated by `postgres: law regression [local] SELECT
                        '.
Program terminated with signal SIGABRT, Aborted.
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
50      ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1  0x00007ff58e5ff859 in __GI_abort () at abort.c:79
#2  0x000055fa508acaaf in ExceptionalCondition (conditionName=0x55fa509407ec
"box->low.y <= box->high.y", 
    errorType=0x55fa5094066a "FailedAssertion", fileName=0x55fa509406fa
"gistproc.c", lineNumber=1240) at assert.c:69
#3  0x000055fa501be673 in computeDistance (isLeaf=false, box=0x7ff5837ff428,
point=0x55fa5122ccf8) at gistproc.c:1240
#4  0x000055fa501bf265 in gist_point_distance (fcinfo=0x7ffdb02e05d0) at
gistproc.c:1466
#5  0x000055fa508b85b4 in FunctionCall5Coll (flinfo=0x55fa5123baa0,
collation=0, arg1=140727559259904, 
    arg2=94533591420152, arg3=15, arg4=600, arg5=140727559259823) at
fmgr.c:1241
#6  0x000055fa501ba284 in gistindex_keytest (scan=0x55fa5123b978,
tuple=0x7ff5837ff420, page=0x7ff5837fd480 "", 
    offset=2, recheck_p=0x7ffdb02e0779, recheck_distances_p=0x7ffdb02e077a)
at gistget.c:286
#7  0x000055fa501ba94c in gistScanPage (scan=0x55fa5123b978,
pageItem=0x7ffdb02e0830, myDistances=0x0, tbm=0x0, 
    ntids=0x0) at gistget.c:438
#8  0x000055fa501bb0f6 in gistgettuple (scan=0x55fa5123b978,
dir=ForwardScanDirection) at gistget.c:639
#9  0x000055fa502190c5 in index_getnext_tid (scan=0x55fa5123b978,
direction=ForwardScanDirection) at indexam.c:533
#10 0x000055fa504a6a85 in IndexOnlyNext (node=0x55fa5123a378) at
nodeIndexonlyscan.c:121
#11 0x000055fa5047b72a in ExecScanFetch (node=0x55fa5123a378,
accessMtd=0x55fa504a64d3 <IndexOnlyNext>, 
    recheckMtd=0x55fa504a6b31 <IndexOnlyRecheck>) at execScan.c:133
#12 0x000055fa5047b7cf in ExecScan (node=0x55fa5123a378,
accessMtd=0x55fa504a64d3 <IndexOnlyNext>, 
    recheckMtd=0x55fa504a6b31 <IndexOnlyRecheck>) at execScan.c:199
#13 0x000055fa504a6bfd in ExecIndexOnlyScan (pstate=0x55fa5123a378) at
nodeIndexonlyscan.c:317
#14 0x000055fa50477458 in ExecProcNodeFirst (node=0x55fa5123a378) at
execProcnode.c:463
#15 0x000055fa5046af44 in ExecProcNode (node=0x55fa5123a378) at
../../../src/include/executor/executor.h:257
#16 0x000055fa5046db62 in ExecutePlan (estate=0x55fa5123a140,
planstate=0x55fa5123a378, use_parallel_mode=false, 
    operation=CMD_SELECT, sendTuples=true, numberTuples=0,
direction=ForwardScanDirection, dest=0x55fa5122d308, 
    execute_once=true) at execMain.c:1551
#17 0x000055fa5046b67b in standard_ExecutorRun (queryDesc=0x55fa511f8ae0,
direction=ForwardScanDirection, count=0, 
    execute_once=true) at execMain.c:361
#18 0x000055fa5046b466 in ExecutorRun (queryDesc=0x55fa511f8ae0,
direction=ForwardScanDirection, count=0, 
    execute_once=true) at execMain.c:305
#19 0x000055fa506ee7c0 in PortalRunSelect (portal=0x55fa511c12c0,
forward=true, count=0, dest=0x55fa5122d308)
    at pquery.c:921
#20 0x000055fa506ee3de in PortalRun (portal=0x55fa511c12c0,
count=9223372036854775807, isTopLevel=true, run_once=true, 
    dest=0x55fa5122d308, altdest=0x55fa5122d308, qc=0x7ffdb02e0d70) at
pquery.c:765
#21 0x000055fa506e7255 in exec_simple_query (
    query_string=0x55fa5114e220 "SELECT f1 <-> point '(0,0)' AS dist FROM
point_tbl ORDER BY dist;") at postgres.c:1215
#22 0x000055fa506ec1ab in PostgresMain (dbname=0x55fa51179b88 "regression",
username=0x55fa51179b68 "law")
    at postgres.c:4498
#23 0x000055fa5060cd49 in BackendRun (port=0x55fa5116f640) at
postmaster.c:4594
#24 0x000055fa5060c5d0 in BackendStartup (port=0x55fa5116f640) at
postmaster.c:4322
#25 0x000055fa506083b8 in ServerLoop () at postmaster.c:1802
#26 0x000055fa50607b15 in PostmasterMain (argc=3, argv=0x55fa511484e0) at
postmaster.c:1474
#27 0x000055fa504f4d81 in main (argc=3, argv=0x55fa511484e0) at main.c:198

With a server compiled without asserts I get:
ERROR:  inconsistent point values

Reproduced on REL_10_STABLE..HEAD.