MySQL Bugs: #60113: plugin names are conflicting with system variable names

Bug #60113	plugin names are conflicting with system variable names
Submitted:	11 Feb 2011 11:53	Modified:	10 Oct 8:22
Reporter:	Sergey Vojtovich	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Options	Severity:	S3 (Non-critical)
Version:	5.6.2	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
This is split from BUG#59017.

It is impossible to install a plugin, if system variable, given at command line, (e.g. "socket") is a prefix of plugin name (e.g. "socket_peercred").

Server is started with --socket=whatever.
When plugin is being installed it exports "socket_peercred" variable with expected values ON|OFF|FORCE|FORCE_PLUS_PERMANENT.
As there is no "socket" variable exported during plugin initialization, getopt expansion does the trick and "socket" is accepted as "socket_peercred", which gets invalid value "whatever".

How to repeat:
Basically the same way as for BUG#59017, but rename plugin back from "auth_socket" to "socket_peercred".

Make sure server is started with --socket.
INSTALL PLUGIN socket_peercred SONAME 'auth_socket.so';
Warnings:
Warning	1123	Can't initialize function 'socket_peercred'; Plugin is disabled
...
101217 15:16:00 [ERROR] /data/mysql/sandbox/5.5.8/bin/mysqld: Error while setting value
'/tmp/mysql55.sock' to 'socket-peercred'
101217 15:16:00 [ERROR] Parsing options for plugin 'socket_peercred' failed.

Suggested fix:
Make plugin names not conflicting with system variable names.

One of possible solutions would be to clean-up arguments that were consumed by the server from arguments array.

Thank you for the report.

Verified as described.

Posted by developer:
 
Option prefixes are removed since 5.7. See e.g. https://dev.mysql.com/doc/refman/5.7/en/program-variables.html

In older versions of MySQL, program options could be specified in full or as any unambiguous prefix. For example, the --compress option could be given to mysqldump as --compr, but not as --comp because the latter is ambiguous. In MySQL 5.7, option prefixes are no longer supported; only full options are accepted. This is because prefixes can cause problems when new options are implemented for programs and a prefix that is currently unambiguous might become ambiguous in the future.