Creating usernames with quotes can break ACL LOAD command after executing ACL SAVE #7329
Description
Through randomised testing we've stumbled on this problem. Creating a user through the ACL SETUSER command that contains a quote symbol is accepted if proper escaping is in place
ACL SETUSER 'test"user' on >redacted ~* +@all
AUTH 'test"user' redacted
OK
ACL SAVE however doesn't incorporate proper escaping when rewriting the acl file. Hence subsequent ACL LOAD commands will fail with:
/redacted/users.acl:10: unbalanced quotes in acl line. WARNING: ACL errors detected, no change to the previously active ACL rules was performed"
e.g. user.acl file
# Unbalanced quotes - ACL LOAD fails
user mXLGgUa"ls;1jW on #66992d25551e...
# Unbalanced quotes - ACL LOAD fails
user "mXLGgUa"ls;1jW" on #66992d25551e...
# ACL LOAD will work but strip out quotes at the beginning at the end of the username
user "mXLGgUa\"ls;1jW" on #66992d25551e...
Expectation would be that either username with single or double quotes are forbidden. Or some kind of escaping is in place to allow single and double quotes in usernames.