[pmg-devel] [PATCH pmg-api] utils: fix mailflow if smtputf8 is disabled

[Stoiko Ivanov <s.ivanov@proxmox.com>]

with the recent addition of smtputf8 support for the rulesystem setups
explicitly disabling smtputf8 in postfix got broken.

This is mostly noticeable for the spamreports (the receivers are taken
from the database and potentially decoded from utf-8, which sets the
'is_utf8' flag, and then tries to use the smtputf8 extension when
reinjecting the mail, which fails (since smtputf8 is disabled)

Instead of checking for the internal flag explicitly check if the
address contains only ascii printable characters (everything excluding
controlcharacters - '[\x20-\x7E]') - see
https://perldoc.perl.org/perlunifaq#What-is-%22the-UTF8-flag%22?
and
https://perldoc.perl.org/perlrecharclass#POSIX-Character-Classes

reported in our community forum:
https://forum.proxmox.com/threads/.119387/

issue is reproducible by setting
`smtputf8_enable = no` in postfix main.cf
and sending a spamreport using `pmgqm`

regular mailflow should not be affected in those setups (as no utf-8
addresses would come into the system)

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
 src/PMG/Utils.pm | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/PMG/Utils.pm b/src/PMG/Utils.pm
index 10193f6..b0a3c52 100644
--- a/src/PMG/Utils.pm
+++ b/src/PMG/Utils.pm
@@ -247,7 +247,7 @@ sub reinject_mail {
 
 	my $has_utf8_targets = 0;
 	foreach my $target (@$targets) {
-	    if (utf8::is_utf8($target)) {
+	    if ($target =~ /[^\p{PosixPrint}]/) {
 		$has_utf8_targets = 1;
 		last;
 	    }
@@ -255,7 +255,7 @@ sub reinject_mail {
 
 	my $mail_opts = " BODY=8BITMIME";
 	my $sender_addr;
-	if (utf8::is_utf8($sender)) {
+	if ($sender =~ /[^\p{PosixPrint}]/) {
 	    $sender_addr = encode('UTF-8', $smtp->_addr($sender));
 	    $mail_opts .= " SMTPUTF8";
 	} else {
@@ -285,7 +285,7 @@ sub reinject_mail {
 		}
 	    }
 
-	    if (utf8::is_utf8($target)) {
+	    if ($sender =~ /[^\p{PosixPrint}]/) {
 		$rcpt_addr = encode('UTF-8', $smtp->_addr($target));
 	    } else {
 		$rcpt_addr = $smtp->_addr($target);
-- 
2.30.2