weird strncmp bug while executing trigger? - Mailing list pgsql-bugs

From Anand
Subject weird strncmp bug while executing trigger?
Date
Msg-id 20020627041755.GA16601@Psmith.blandings.com
Whole thread Raw
Responses Re: weird strncmp bug while executing trigger?
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============================================================================
                        POSTGRESQL BUG REPORT TEMPLATE
============================================================================


Your name        :    Anand Ranganathan
Your email address    : anand@blandings.com


System Configuration
---------------------
  Architecture (example: Intel Pentium)      : Intel Pentium

  Operating System (example: Linux 2.0.26 ELF)     : Linux 2.2.19 ELF (Debian unstable)

  PostgreSQL version (example: PostgreSQL-7.1.3):   PostgreSQL-7.2.1

  Compiler used (example:  gcc 2.95.2)        :  gcc 2.95.4 20011002 (Debian prerelease)


Please enter a FULL description of your problem:
------------------------------------------------
When I run the select statement given below, the postgres server dies on
a SIGSEGV. This is quite annoying.




Please describe a way to repeat the problem.   Please try to provide a
concise reproducible example, if at all possible:
----------------------------------------------------------------------

Between the dashed lines is the output of pg_dump
------------pg_dump output---------------------------
--
-- Selected TOC Entries:
--
\connect - anand

--
-- TOC Entry ID 11 (OID 16623)
--
-- Name: "plpgsql_call_handler" () Type: FUNCTION Owner: anand
--

CREATE FUNCTION "plpgsql_call_handler" () RETURNS opaque AS '/bp/vendor/lib/plpgsql.so', 'plpgsql_call_handler'
LANGUAGE'C'; 

--
-- TOC Entry ID 12 (OID 16624)
--
-- Name: plpgsql Type: PROCEDURAL LANGUAGE Owner:
--

CREATE TRUSTED PROCEDURAL LANGUAGE 'plpgsql' HANDLER "plpgsql_call_handler" LANCOMPILER 'PL/pgSQL';

--
-- TOC Entry ID 13 (OID 16625)
--
-- Name: "insert_comment" () Type: FUNCTION Owner: anand
--

CREATE FUNCTION "insert_comment" () RETURNS opaque AS 'DECLARE profile RECORD;
            BEGIN
                SELECT INTO profile * FROM uid_profile WHERE uid = new.uid;
                IF profile.signature <> ''''
                THEN
                new.description = new.description || ''<br>-- <br>'' || profile.signature;
                END IF;
                RETURN new;
            END;' LANGUAGE 'plpgsql';

--
-- TOC Entry ID 4 (OID 16626)
--
-- Name: uid_profile Type: TABLE Owner: anand
--

CREATE TABLE "uid_profile" (
    "uid" integer NOT NULL,
    "username" text,
    "karma" integer DEFAULT 0,
    "user_type" character(1) DEFAULT 'R',
    "last_access" timestamp with time zone DEFAULT "timestamp"('now'::text),
    "mod_worthy" integer DEFAULT 0,
    "min_threshold" integer DEFAULT 1,
    "display_type" character(1) DEFAULT 'F',
    "signature" text DEFAULT '',
    "timezone" text DEFAULT 'PST',
    "spam_mail" text DEFAULT '',
    Constraint "uid_profile_pkey" Primary Key ("uid")
);

--
-- TOC Entry ID 2 (OID 16768)
--
-- Name: comments_cid_seq Type: SEQUENCE Owner: anand
--

CREATE SEQUENCE "comments_cid_seq" start 1 increment 1 maxvalue 2147483647 minvalue 1 cache 1;

--
-- TOC Entry ID 5 (OID 16770)
--
-- Name: comments Type: TABLE Owner: anand
--

CREATE TABLE "comments" (
    "aid" integer,
    "subject" text,
    "description" text,
    "uid" integer,
    "when_posted" timestamp with time zone DEFAULT "timestamp"('now'::text),
    "modvalue" integer DEFAULT 1,
    "lastmod" integer DEFAULT 1,
    "parent" integer DEFAULT 0,
    "posting_uid" integer,
    "posting_user" text,
    "cid" integer DEFAULT nextval('"comments_cid_seq"'::text) NOT NULL,
    Constraint "comments_pkey" Primary Key ("cid")
);

--
-- Data for TOC Entry ID 14 (OID 16626)
--
-- Name: uid_profile Type: TABLE DATA Owner: anand
--


COPY "uid_profile" FROM stdin;
1000001    axl rose    31    E    2002-03-08 19:35:38-08    70    1    F        PST
\.
--
-- Data for TOC Entry ID 15 (OID 16770)
--
-- Name: comments Type: TABLE DATA Owner: anand
--


COPY "comments" FROM stdin;
\.
--
-- TOC Entry ID 6 (OID 17046)
--
-- Name: "comments_uid_index" Type: INDEX Owner: anand
--

CREATE INDEX comments_uid_index ON comments USING btree (uid);

--
-- TOC Entry ID 7 (OID 17047)
--
-- Name: "comments_modvalue_index" Type: INDEX Owner: anand
--

CREATE INDEX comments_modvalue_index ON comments USING btree (modvalue);

--
-- TOC Entry ID 8 (OID 17048)
--
-- Name: "comments_parent_index" Type: INDEX Owner: anand
--

CREATE INDEX comments_parent_index ON comments USING btree (parent);

--
-- TOC Entry ID 9 (OID 17049)
--
-- Name: "comments_posting_user_index" Type: INDEX Owner: anand
--

CREATE INDEX comments_posting_user_index ON comments USING btree (posting_user);

--
-- TOC Entry ID 10 (OID 17050)
--
-- Name: "comments_aid_index" Type: INDEX Owner: anand
--

CREATE INDEX comments_aid_index ON comments USING btree (aid);

--
-- TOC Entry ID 16 (OID 17072)
--
-- Name: comment_insert_trigger Type: TRIGGER Owner: anand
--

CREATE TRIGGER "comment_insert_trigger" BEFORE INSERT ON "comments"  FOR EACH ROW EXECUTE PROCEDURE "insert_comment"
();

--
-- TOC Entry ID 3 (OID 16768)
--
-- Name: comments_cid_seq Type: SEQUENCE SET Owner: anand
--

SELECT setval ('"comments_cid_seq"', 62, true);

------------end pg_dump output-----------------------

After this is loaded into a database (mine is called dot):
createdb dot
psql dot < dump_file
execute this command at the
"psql dot" prompt.

INSERT INTO comments (aid, uid, subject, description, parent, posting_uid, posting_user) VALUES (12, 1000001, 'hello
world','here is a comment', 0, 1000001, 'a'); 

When I do that the postgres server that the psql process is connected to
dies on a sig segv.

Here's the backtrace from gdb:

(gdb) bt
#0  0x4012a6b3 in strncmp () from /lib/libc.so.6
#1  0x403980fa in ?? ()
#2  0x40395916 in ?? ()
#3  0x080baafb in ExecCallTriggerFunc (trigdata=0xbfffe718, finfo=0x82486c8,
    per_tuple_context=0x825a5b8) at trigger.c:886
#4  0x080bac4f in ExecBRInsertTriggers (estate=0x82480a0, relinfo=0x8248470,
    trigtuple=0x8247e38) at trigger.c:934
#5  0x080c220c in ExecAppend (slot=0x82484b8, tupleid=0x0, estate=0x82480a0)
    at execMain.c:1233
#6  0x080c2139 in ExecutePlan (estate=0x82480a0, plan=0x8248018,
    operation=CMD_INSERT, numberTuples=0, direction=ForwardScanDirection,
    destfunc=0x8248688) at execMain.c:1119
#7  0x080c1587 in ExecutorRun (queryDesc=0x8247be8, estate=0x82480a0,
    feature=3, count=0) at execMain.c:233
#8  0x0810dfbe in ProcessQuery (parsetree=0x8245fb0, plan=0x8248018,
    dest=Remote, completionTag=0xbfffe890 "") at pquery.c:259
#9  0x0810c860 in pg_exec_query_string (
    query_string=0x8245938 "INSERT INTO comments (aid, uid, subject, description, parent, posting_uid, posting_user)
VALUES(12, 1000001, 'hello world', 'here is a comment', 0, 1000001, 'a');", dest=Remote, parse_context=0x821c2e8) 
    at postgres.c:811
#10 0x0810d83e in PostgresMain (argc=4, argv=0xbfffeac0,
    username=0x8217e71 "anand") at postgres.c:1926
#11 0x080f4ebe in DoBackend (port=0x8217d40) at postmaster.c:2243
#12 0x080f480f in BackendStartup (port=0x8217d40) at postmaster.c:1874
#13 0x080f3a92 in ServerLoop () at postmaster.c:995
#14 0x080f35ab in PostmasterMain (argc=2, argv=0x81ed928) at postmaster.c:771
#15 0x080d3095 in main (argc=2, argv=0xbffff444) at main.c:206
(gdb)



If you know how this problem might be fixed, list the solution below:
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