BUG #19778: Empty tsquery cannot roundtrip through binary input
Hackorum builds and tests every patch posted to the lists, not only commitfest submissions. This is Hackorum's own CI rather than the PostgreSQL project's, and it is still under testing - please report anything that looks wrong.
This thread has been committed, so CI has stopped here. Anything below is the last result it produced.
You can run a PostgreSQL built from this patch straight from Docker, with no checkout and no build:
docker run --rm -p 5432:5432 ghcr.io/hackorum-dev/postgres-patch:t254325psql -h localhost -U postgresBuilt from patchset v2 (message #2), October 22, 2026 at 05:05 PM.
Every patchset is also pushed to a branch of our PostgreSQL fork, so you can check out the same tree CI built. Without a PostgreSQL checkout:
git clone --branch t254325_2 https://github.com/hackorum-dev/postgres.gitIn a checkout you already have, add the fork once:
git remote add hackorum https://github.com/hackorum-dev/postgres.gitthen, for this patchset and every later one:
git fetch hackorum t254325_2 && git checkout t254325_2Patchset v2 (message #2) is on t254325_2
The following bug has been logged on the website:
Bug reference: 19778
Logged by: Shay Rojansky
Email address: roji@roji.org
PostgreSQL version: 18.4
Operating system: macOS Tahoe 26.7.1
Description:
It appears that an empty binary tsquery cannot be written to PostgreSQL.
Writing a non-empty binary tsquery works, as well as writing an empty text
tsquery.
Minimal repro:
#include <libpq-fe.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static void require_row(PGresult *result)
{
if (PQresultStatus(result) != PGRES_TUPLES_OK || PQntuples(result) != 1)
{
fprintf(stderr, "Unexpected result: %s",
PQresultErrorMessage(result));
exit(1);
}
}
int main(int argc, char **argv)
{
PGconn *conn = PQconnectdb(argc > 1 ? argv[1] : "dbname=postgres");
if (PQstatus(conn) != CONNECTION_OK)
{
fprintf(stderr, "%s", PQerrorMessage(conn));
PQfinish(conn);
return 1;
}
printf("libpq=%d, PostgreSQL=%d\n", PQlibVersion(),
PQserverVersion(conn));
/* Obtain both binary values from PostgreSQL, without constructing
either. */
PGresult *values = PQexecParams(
conn, "SELECT ''::tsquery, 'foo'::tsquery",
0, NULL, NULL, NULL, NULL, 1);
require_row(values);
const Oid types[] = {PQftype(values, 0)};
const char *params[] = {PQgetvalue(values, 0, 1)};
int lengths[] = {PQgetlength(values, 0, 1)};
int formats[] = {1};
PGresult *result = PQexecParams(conn, "SELECT $1", 1, types, params,
lengths, formats, 0);
require_row(result);
if (PQgetisnull(result, 0, 0) || strcmp(PQgetvalue(result, 0, 0),
"'foo'") != 0)
return 1;
printf("Binary non-empty tsquery roundtrip: %s\n", PQgetvalue(result, 0,
0));
PQclear(result);
params[0] = "";
lengths[0] = 0;
formats[0] = 0;
result = PQexecParams(conn, "SELECT $1", 1, types, params, lengths,
formats, 0);
require_row(result);
if (PQgetisnull(result, 0, 0) || PQgetlength(result, 0, 0) != 0)
return 1;
puts("Text empty tsquery roundtrip: OK");
PQclear(result);
params[0] = PQgetvalue(values, 0, 0);
lengths[0] = PQgetlength(values, 0, 0);
formats[0] = 1;
printf("Server-produced empty tsquery: type=%u, format=%d, length=%d,
hex=",
types[0], PQfformat(values, 0), lengths[0]);
for (int i = 0; i < lengths[0]; i++)
printf("%02x", (unsigned char)params[0][i]);
putchar('\n');
/* Send the server's bytes back unchanged, with the server's type OID.
*/
result = PQexecParams(conn, "SELECT $1", 1, types, params, lengths,
formats, 0);
const char *state = PQresultErrorField(result, PG_DIAG_SQLSTATE);
const char *message = PQresultErrorField(result,
PG_DIAG_MESSAGE_PRIMARY);
const char *routine = PQresultErrorField(result,
PG_DIAG_SOURCE_FUNCTION);
int reproduced = PQresultStatus(result) == PGRES_FATAL_ERROR
&& state && strcmp(state, "XX000") == 0
&& message && strcmp(message, "malformed tsquery: operand not
found") == 0
&& routine && strcmp(routine, "findoprnd_recurse") == 0;
if (reproduced)
printf("REPRODUCED: %s: %s (%s)\n", state, message, routine);
else
fprintf(stderr, "Expected server error was not reproduced: %s\n",
PQresultErrorMessage(result));
PQclear(result);
PQclear(values);
PQfinish(conn);
return reproduced ? 0 : 1;
}
Hi,
On Thu, 22 Oct 2026 at 11:58, PG Bug reporting form
<noreply@postgresql.org> wrote:
The following bug has been logged on the website:
Bug reference: 19778
Logged by: Shay Rojansky
Email address: roji@roji.org
PostgreSQL version: 18.4
Operating system: macOS Tahoe 26.7.1
Description:It appears that an empty binary tsquery cannot be written to PostgreSQL.
Writing a non-empty binary tsquery works, as well as writing an empty text
tsquery.Minimal repro:
#include <libpq-fe.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>static void require_row(PGresult *result)
{
if (PQresultStatus(result) != PGRES_TUPLES_OK || PQntuples(result) != 1)
{
fprintf(stderr, "Unexpected result: %s",
PQresultErrorMessage(result));
exit(1);
}
}int main(int argc, char **argv)
{
PGconn *conn = PQconnectdb(argc > 1 ? argv[1] : "dbname=postgres");
if (PQstatus(conn) != CONNECTION_OK)
{
fprintf(stderr, "%s", PQerrorMessage(conn));
PQfinish(conn);
return 1;
}
printf("libpq=%d, PostgreSQL=%d\n", PQlibVersion(),
PQserverVersion(conn));/* Obtain both binary values from PostgreSQL, without constructing
either. */
PGresult *values = PQexecParams(
conn, "SELECT ''::tsquery, 'foo'::tsquery",
0, NULL, NULL, NULL, NULL, 1);
require_row(values);
const Oid types[] = {PQftype(values, 0)};
const char *params[] = {PQgetvalue(values, 0, 1)};
int lengths[] = {PQgetlength(values, 0, 1)};
int formats[] = {1};PGresult *result = PQexecParams(conn, "SELECT $1", 1, types, params,
lengths, formats, 0);
require_row(result);
if (PQgetisnull(result, 0, 0) || strcmp(PQgetvalue(result, 0, 0),
"'foo'") != 0)
return 1;
printf("Binary non-empty tsquery roundtrip: %s\n", PQgetvalue(result, 0,
0));
PQclear(result);params[0] = "";
lengths[0] = 0;
formats[0] = 0;
result = PQexecParams(conn, "SELECT $1", 1, types, params, lengths,
formats, 0);
require_row(result);
if (PQgetisnull(result, 0, 0) || PQgetlength(result, 0, 0) != 0)
return 1;
puts("Text empty tsquery roundtrip: OK");
PQclear(result);params[0] = PQgetvalue(values, 0, 0);
lengths[0] = PQgetlength(values, 0, 0);
formats[0] = 1;
printf("Server-produced empty tsquery: type=%u, format=%d, length=%d,
hex=",
types[0], PQfformat(values, 0), lengths[0]);
for (int i = 0; i < lengths[0]; i++)
printf("%02x", (unsigned char)params[0][i]);
putchar('\n');/* Send the server's bytes back unchanged, with the server's type OID.
*/
result = PQexecParams(conn, "SELECT $1", 1, types, params, lengths,
formats, 0);
const char *state = PQresultErrorField(result, PG_DIAG_SQLSTATE);
const char *message = PQresultErrorField(result,
PG_DIAG_MESSAGE_PRIMARY);
const char *routine = PQresultErrorField(result,
PG_DIAG_SOURCE_FUNCTION);
int reproduced = PQresultStatus(result) == PGRES_FATAL_ERROR
&& state && strcmp(state, "XX000") == 0
&& message && strcmp(message, "malformed tsquery: operand not
found") == 0
&& routine && strcmp(routine, "findoprnd_recurse") == 0;
if (reproduced)
printf("REPRODUCED: %s: %s (%s)\n", state, message, routine);
else
fprintf(stderr, "Expected server error was not reproduced: %s\n",
PQresultErrorMessage(result));PQclear(result);
PQclear(values);
PQfinish(conn);
return reproduced ? 0 : 1;
}
Thanks for the report, I can reproduce this on master too.
tsqueryrecv() calls findoprnd() even for an empty query, and that
fails with "malformed tsquery: operand not found". The text input
doesn't have this problem since parse_tsquery() returns early for an
empty query.
Attached is a patch that skips findoprnd() when size is 0.
IIUC, this goes back to all supported branches, and logical
replication with binary = true would hit it too. Which is why I'm
somewhat in favour of backpatching for this.
Regards,
Ayush
Ayush Tiwari <ayushtiwari.slg01@gmail.com> writes:
On Thu, 22 Oct 2026 at 11:58, PG Bug reporting form
<noreply@postgresql.org> wrote:It appears that an empty binary tsquery cannot be written to PostgreSQL.
Thanks for the report, I can reproduce this on master too.
Yeah, you can duplicate it without extra moving parts using
binary COPY out and then in.
tsqueryrecv() calls findoprnd() even for an empty query, and that
fails with "malformed tsquery: operand not found". The text input
doesn't have this problem since parse_tsquery() returns early for an
empty query.
Attached is a patch that skips findoprnd() when size is 0.
+1, will push.
regards, tom lane