BUG #15542: value too long for type character varying does not show the real parameter value

The following bug has been logged on the website:

Bug reference: 15542
Logged by: Stefan Lindner
Email address: lindner(at)visionet(dot)de
PostgreSQL version: 10.6
Operating system: CentOS 7.5, official docker container postgres:10
Description:

2018-12-07 13:47:48.047 UTC [63] ERROR: 22001: value too long for type
character varying(6)
2018-12-07 13:47:48.047 UTC [63] LOCATION: varchar, varchar.c:624
2018-12-07 13:47:48.047 UTC [63] STATEMENT: update visionet_berechnung set
adresse=$1, anmerkungen=$2, ANREDE_IN_VERSAND_E_MAIL=$3, datum=$4, kunde=$5,
MANUELLER_TEXT_AUF_BERECHNUNG=$6, steuersatz=$7, stundensatz=$8,
VERSAND_PER_E_MAIL_AN=$9, zusammenfassung=$10, aktualisierungsdatum=$11,
loesch_datum=$12, loesch_erklaerung=$13, nettosumme=$14, nummer=$15,
pdf=$16, prozent_abgerechnet=$17, status=$18, steuer=$19, summe=$20,
tex_code=$21, versandinformation=$22, versanddatum=$23 where id=$24

even having set parameters
log_statement=all
log_error_verbosity=VERBOSE
the value for column with more than 6 characters is not shown.

In all other logged queries before there ware lines like
DETAIL: parameters: $1 = '13533', $2 = 't', $3 = '257', $4 = '28', $5 =
'1298'
and so on. But not for the erroneous statement.