This geometry causes buffer(?, 0) to crash the PostGresql server

[dstahlke]

What steps will reproduce the problem?

1. Run the attached script

2. 3.

What is the expected output? What do you see instead?

server closed the connection unexpectedly

This probably means the server terminated abnormally before or while processing the request.

connection to server was lost

What version of the product are you using? On what operating system?

psql 8.3.5 postgis_version: 1.3 USE_GEOS=1 USE_PROJ=1 USE_STATS=1 postgis_geos_version: 3.0.1-CAPI-1.4.2 Fedora 10

Please provide any additional information below.

The following is written to the log file:

bufferOriginalPrecision failed (TopologyException: unable to assign hole to a shell), trying with reduced precision recomputing with precision scale factor = 1e+09 Scaler: offsetX,Y: 0,0 scaleFactor: 1e+09

dstahlke svdev [local] SELECT:

../../source/headers/geos/noding/SegmentString.h:175: void geos::noding::SegmentString::testInvariant() const: Assertion `pts→size()

1' failed.

LOG: server process (PID 863) was terminated by signal 6: Aborted LOG: terminating any other active server processes LOG: all server processes terminated; reinitializing LOG: database system was interrupted; last known up at 2008-12-05 14:16:19 AKST LOG: database system was not properly shut down; automatic recovery in progress LOG: record with zero length at 0/3C5BC340 LOG: redo is not required LOG: database system is ready to accept connections LOG: autovacuum launcher started

[robe]

I confirmed that this happens on 'POSTGIS='1.3.3' GEOS='3.0.0-CAPI-1.4.1' PROJ='Rel. 4.6.0, 21 Dec 2007' (windows 8.3.4)

and on OpenSuse 11 8.3.1 'POSTGIS='1.4.0SVN' GEOS='3.1.0-CAPI-1.5.0' PROJ='Rel. 4.6.0, 21 Dec 2007'

so appears to be long standing GEOS bug.

[mcayland]

In that case, this is probably a 'WontFix' and should be reposted onto the GEOS tracker at ​http://trac.osgeo.org/geos. Anyone object?

ATB,

Mark.

[robe]

I don't object. I was thinking of doing the same thing but didn't think I was knowledgable enough to make the call. I'll go ahead and repost to GEOS group.

[dstahlke]

​http://postgis.googlecode.com/issues/attachment?aid=-8745173399194014760&name=geos-bug.sql

[mcayland]

Ah I see. Normally the procedure is to try the geometry in GEOS by converting to XMLTester format, and if it crashes there then it's definitely a GEOS rather than PostGIS issue.

HTH,

Mark.