it should also be figured out what to do about duplicate valid params.
complain & exit ? complain & continue ?
continuing might be required in scenarios where users use includes to override defaults. in that case it should be logged which value was eventually used (which seems to be the last one encountered)
of course, it should not complain about params that may be repeated, for example, UserParameter 
also, specifying two userparams with the same key should be checked.
(1) Please, see my changes in revision 19172. Small refactoring
<CLOSED>
(2) Error, while starting Zabbix agent: zabbix_agentd [15777]: unknown parameter [EnableRemoteCommands] in line 62
The "EnableRemoteCommands" parameter supported by Zabbix agent
<sasha> CLOSED
this will help with many, many problems... like http://www.zabbix.com/forum/showthread.php?t=21733
(3) what about repeated valid parameters ?
<dimir> Currently it works so that it won't stop on first parameter match to get the value, it will continue till the end of the file and will everytime assign new value. By the way, this leads to a memory leaks in case of string type parameters, as it every time does strdup() the value.
<dimir> In order to identify duplicate parameters in configuration I guess we would need to either modify cfg_line structure to add field something like "set" (0/1) or track it in load_config() storing all the read parameters in array or something.
<richlv> i guess memleak has been fixed ? warning about repeated parameters has been filed as a new issue ZBXNEXT-770
<dimir> CLOSED. We have decided to silently replace repeated valid parameters.
Fixed in version 1.8.6rc1, r19285, r19287.
Merged from upstream, resolved the conflicts with PerfCounter changes done by Rudolfs. Need to test those now.
Fixed in dev branch ZBX-3105, r19419.
Fixed in branches/dev/ZBX-3105, r19464.
(19) please make sure to document all the decision/changes for both 1.8 & 2.0 
<dimir> Please review my changes for each Zabbix process in 1.8: http://www.zabbix.com/documentation/1.8/manual/processes . You can search for '1.8.6' string to get the changes. 2.0 is coming up.
<dimir> After some discussions with Rich fixed those for 1.8, please review. As for 2.0 I'm not sure where this information should belong, perhaps http://www.zabbix.com/documentation/2.0/manual/concepts ?
<dimir> RESOLVED, please confirm changes in 1.8 . As discussed on IRC with zalex and Rich there is nothing to add to 2.0 at this moment as the changes apply to both 1.8 and 2.0 in the same way.
Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-3105-trunk .
Fixed in trunk r19869, 1.8 r19813 .
(23) Regression: "Include" parameter is not recognized anymore:
$ sbin/zabbix_agentd
zabbix_agentd [307]: unknown parameter [Include] in config file [/etc/zabbix/zabbix_agentd.conf], line 4
<dimir> RESOLVED
<sasha> CLOSED
Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-3105 .
Fixed in trunk 19908 , 1.8 19907 .
Reopening to fix "Fix versions".
daemons calling user input garbage reported as ZBX-4087