Bug#944199: exim4: dsearch in config end up in exim4 panic

[Benedikt Spranger]

Package: exim4
Version: 4.93~RC1-2
Severity: important

Dear Maintainer,

using a virtual domain config as described in the current exim manual
https://www.exim.org/exim-html-current/doc/html/spec_html/ch-some_common_configuration_settings.html#SECTvirtualdomains

renders exim4 unusable.

Config files:
# ls /etc/exim4/virtual
example.com
#

Config snippet:
virtual:
  driver = redirect
  domains = dsearch;/etc/mail/virtual
  data = ${lookup{$local_part}lsearch{/etc/mail/virtual/$domain}}
  no_more

Error (paniclog):
2019-11-05 17:27:01 1iRbGs-0000X0-9x Taint mismatch, string_vformat: dsearch_find 87
2019-11-05 17:27:50 Taint mismatch, string_vformat: dsearch_find 87

Regards
    Benedikt Spranger