8.2beta1 crash possibly in libpq - Mailing list pgsql-hackers

Hi everyone,

I'm in the process of generating the Windows installer for the latest
PostGIS 1.1.4 release and I'm getting a regression failure in one of
libpq applications - the application in question is generating a
segfault.

Testing so far shows that the regression tests pass without segfaulting
in the following scenarios:

PostgreSQL 8.2beta1 / PostGIS 1.1.4 / Linux
PostgreSQL 8.1 / PostGIS 1.1.4 / Win32

So it appears it is something to do with 8.2beta1 and Win32. I've
compiled the application with debugging symbols enabled and get the
following backtrace from gdb in MingW:


(gdb) set args -f /tmp/pgis_reg_4060/dumper postgis_reg loadedshp
(gdb) run
Starting program: C:\msys\1.0\home\mca\postgis\pg82\postgis-1.1.4
\regress/../loader/pgsql2shp.exe -f /tmp/pgis_reg_4060/dumper
postgis_reg loadedshp
Initializing... 
Program received signal SIGSEGV, Segmentation fault.
0x63512c1c in ?? ()
(gdb) bt
#0  0x63512c1c in ?? ()
#1  0x0040c69c in _fu8__PQntuples () at pgsql2shp.c:2502
#2  0x00408481 in main (ARGC=5, ARGV=0x3d2750) at pgsql2shp.c:243
(gdb) 


I also turned on the logging in the server and get the following in the
server log:


2006-10-08 12:01:15 LOG:  statement: BEGIN;
2006-10-08 12:01:15 LOG:  statement: CREATE TABLE "loadedshp" (gid
serial PRIMARY KEY);
2006-10-08 12:01:15 NOTICE:  CREATE TABLE will create implicit sequence
"loadedshp_gid_seq" for serial column "loadedshp.gid"
2006-10-08 12:01:15 NOTICE:  CREATE TABLE / PRIMARY KEY will create
implicit index "loadedshp_pkey" for table "loadedshp"
2006-10-08 12:01:15 LOG:  statement: SELECT
AddGeometryColumn('','loadedshp','the_geom','-1','POINT',2);
2006-10-08 12:01:17 LOG:  statement: INSERT INTO "loadedshp" (the_geom)
VALUES ('01010000000000000000000000000000000000F03F');
2006-10-08 12:01:18 LOG:  statement: INSERT INTO "loadedshp" (the_geom)
VALUES ('01010000000000000000002240000000000000F0BF');
2006-10-08 12:01:18 LOG:  statement: INSERT INTO "loadedshp" (the_geom)
VALUES ('01010000000000000000002240000000000000F0BF');
2006-10-08 12:01:18 LOG:  statement: END;
2006-10-08 12:01:21 LOG:  statement: select asewkt(the_geom) from
loadedshp;
2006-10-08 12:01:36 LOG:  statement: DROP table loadedshp
2006-10-08 12:01:39 LOG:  statement: BEGIN;
2006-10-08 12:01:39 LOG:  statement: CREATE TABLE "loadedshp" (gid
serial PRIMARY KEY);
2006-10-08 12:01:39 NOTICE:  CREATE TABLE will create implicit sequence
"loadedshp_gid_seq" for serial column "loadedshp.gid"
2006-10-08 12:01:39 NOTICE:  CREATE TABLE / PRIMARY KEY will create
implicit index "loadedshp_pkey" for table "loadedshp"
2006-10-08 12:01:39 LOG:  statement: SELECT
AddGeometryColumn('','loadedshp','the_geom','-1','POINT',2);
2006-10-08 12:01:41 LOG:  statement: COPY "loadedshp" (the_geom) FROM
stdin;
2006-10-08 12:01:41 LOG:  statement: END;
2006-10-08 12:01:43 LOG:  statement: select asewkt(the_geom) from
loadedshp;
2006-10-08 12:02:34 LOG:  statement: SELECT postgis_version()
2006-10-08 12:02:34 LOG:  statement: SELECT a.attname, a.atttypid,
a.attlen, a.atttypmod FROM pg_attribute a, pg_class c WHERE a.attrelid =
c.oid and a.attnum > 0 AND a.atttypid != 0 AND c.relname = 'loadedshp'
2006-10-08 12:02:48 LOG:  could not receive data from client: No
connection could be made because the target machine actively refused
it.
2006-10-08 12:02:48 LOG:  unexpected EOF on client connection


AFAICT the backtrace and server log is indicating that the crash is
happening somewhere in libpq. If someone can help me figure out how to
load the libpq symbols into MingW's gdb then I can get a better
backtrace if required as I can reproduce this 100% of the time. For
reference, the source for the application in question can be found at
http://svn.refractions.net/postgis/tags/1.1.4/loader/pgsql2shp.c.


Many thanks,

Mark.