pgx.CopyFromRows does not work with tsvector column in destination table

[spongenee]

Describe the bug
pgx.CopyFromRows does not work with tsvector column in destination table. No data is copied to destination table.

The error is:

CopyFrom error: ERROR: invalid size of tsvector (SQLSTATE XX000)

If I alter the tsvector column in destination table to TEXT, then Copying from table with a tsvector column works. And I can alter the column to tsvector again. so it's clearly not a size issue of the source data.

To Reproduce
Steps to reproduce the behavior:

package main

import (
	"context"
	"fmt"
	"os"
	"time"
	"github.com/jackc/pgx/v5"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	dsn := os.Getenv("DATABASE_URL")
	if dsn == "" {
		fmt.Fprintln(os.Stderr, "Please set DATABASE_URL, e.g.: export DATABASE_URL=\"postgres://user:pass@host:5432/dbname?sslmode=disable\"")
		os.Exit(1)
	}

	conn, err := pgx.Connect(ctx, dsn)
	if err != nil {
		fmt.Fprintf(os.Stderr, "connect error: %v\n", err)
		os.Exit(1)
	}
	defer conn.Close(ctx)

	_, err = conn.Exec(ctx, `CREATE TEMP TABLE tmp_tsv (id int, t tsvector)`)
	if err != nil {
		fmt.Fprintf(os.Stderr, "create table error: %v\n", err)
		os.Exit(1)
	}

	rows := [][]any{
		{1, "'3c3':4B 'annabel':1A 'm6k':3B 's':2A 'toronto':5"},
	}

	n, err := conn.CopyFrom(ctx, pgx.Identifier{"tmp_tsv"}, []string{"id", "t"}, pgx.CopyFromRows(rows))
	if err != nil {
		fmt.Fprintf(os.Stderr, "CopyFrom error: %v\n", err)
		os.Exit(1)
	}

	fmt.Printf("copy result: n=%d err=%v\n", n, err)
}

This is the test code I used, and it returns:

$ go run -race main.go
CopyFrom error: ERROR: invalid size of tsvector (SQLSTATE XX000)
exit status 1

To run it, export DATABASE_URL=<db_url> before go run -race main.go.

Expected behavior
Copy should be successful and exit with status 0.

Actual behavior
Returns error above and no data copied to destination table.

Version

• Go: $ go version -> [e.g. go version go1.18.3 darwin/amd64]
  go version go1.25.6 linux/amd64
• PostgreSQL: $ psql --no-psqlrc --tuples-only -c 'select version()' -> [e.g. PostgreSQL 14.4 on x86_64-apple-darwin21.5.0, compiled by Apple clang version 13.1.6 (clang-1316.0.21.2.5), 64-bit]
  PostgreSQL 15.10 on x86_64-pc-linux-gnu, compiled by x86_64-pc-linux-gnu-gcc (GCC) 9.5.0, 64-bit
• pgx: $ grep 'github.com/jackc/pgx/v[0-9]' go.mod -> [e.g. v4.16.1]
  github.com/jackc/pgx/v5 v5.8.0

Additional context
Add any other context about the problem here.