Crash with points_as_polygon()

[stefan]

Hi list,

i just found out, that points_as_polygon() can crash/restart the whole postgresql database under certain circumstances. my case is: i use points_as_polygon() to get a nice polygon from the result which is returned by driving_distance(). my result from driving_distance() is the following: as you can see, i have only two points in this result. i know that it is not possible to generate a polygon from only two points. but at least i would expect pgrouting to return either an empty polygon or to return nothing without crashing the database.

i think the bug sticks in the alphashape() c-function. any ideas?

SELECT points_as_polygon('SELECT p.id, p.x, p.y FROM points_as_polygon_crash AS p');

-- PostgreSQL database dump CREATE TABLE points_as_polygon_crash (id integer, x double precision, y double precision);

INSERT INTO points_as_polygon_crash VALUES (422072, 12.474746700000001, 51.347863599999997); INSERT INTO points_as_polygon_crash VALUES (438668, 12.475282999999999, 51.349685000000001);

i use pgrouting 1.02

select version() PostgreSQL 8.2.4 on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)

select postgis_full_version() POSTGIS="1.3.3" GEOS="3.0.3-CAPI-1.4.2" PROJ="Rel. 4.6.0, 21 Dec 2007" USE_STATS

this is what server.log says to the points_as_polygon query:

LOG: server process (PID 16153) was terminated by signal 11 LOG: terminating any other active server processes WARNING: terminating connection because of crash of another server process DETAIL: The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory. HINT: In a moment you should be able to reconnect to the database and repeat your command. WARNING: terminating connection because of crash of another server process DETAIL: The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory. HINT: In a moment you should be able to reconnect to the database and repeat your command. LOG: all server processes terminated; reinitializing LOG: database system was interrupted at 2009-04-03 10:21:31 CEST LOG: checkpoint record is at 210/95202CF8 LOG: redo record is at 210/95202CF8; undo record is at 0/0; shutdown FALSE LOG: next transaction ID: 0/309385647; next OID: 2123543 LOG: next MultiXactId?: 1; next MultiXactOffset?: 0 LOG: database system was not properly shut down; automatic recovery in progress LOG: record with zero length at 210/95202D48 LOG: redo is not required LOG: database system is ready

[Chewi]

Don't seem to be able to CC myself to this but I'd like to know when this is fixed.