when fixing this, it should be decided what to do upon user/host group removal - script can't be made available to all user groups on all host groups, that would be a security issue

Decided that a user group can't be deleted if it is used in script. Host group used also can't be deleted.

Fixed in dev branch: ZBX-2862

Usergroups and hostgroups used in scripts can't be deleted

while functionally it seems to work as expected in the dev branch, there seem to be some minor issues.

the frontend errors are :
Group "deleteme" can not be deleted, because it is used in script "deleteme"
[ CUserGroup::delete ] You cannot delete user group used in a script: group [deleteme] is used in script [deleteme]

1. error messages are missing the trailing dot (as discussed before);

2. inconsistent messages.
2.1. it should be decided whether entity references (like names here) should be doublequoted or enclosed in square brackets - or any other style.
2.2. usergroup message also probably should be rewritten in a more formal way :
User group [deleteme] can not be deleted because it is used in script [deleteme]
2.3. hostgroup message never says what kind of a group that is - should say "Host group" at the beginning of the message

3. usergroup deletion api responses
3.1. weird api reaction to incorrect queries :

{"jsonrpc":"2.0","method":"usergroup.delete","params":

,"auth":"de42619ff2871b5be5e0fc84192ff2fe","id":4}
Response Code: 200
Response Body: {"jsonrpc":"2.0","result":

,"id":4}

{"jsonrpc":"2.0","method":"usergroup.delete","params":

,"auth":"de42619ff2871b5be5e0fc84192ff2fe","id":5}
Response Code: 200
Response Body: {"jsonrpc":"2.0","error":

,"id":5}

3.2. response to correct syntax includes nbsp - should it be there ?
"data":"[ CUserGroup::delete ] You cannot delete user group used in a script: group [deleteme] is used in script [deleteme]"

4. attempting to delete such a hostgroup never gives out the real reason (although with the api syntax being quite inconsistent, i'm not really sure i'm using a correct syntax in any of these queries
{"jsonrpc":"2.0","method":"hostgroup.delete","params":[

],"auth":"de42619ff2871b5be5e0fc84192ff2fe","id":5}
Response Code: 200
Response Body: {"jsonrpc":"2.0","error":

,"id":5}

Response Code: 200
Response Body: {"jsonrpc":"2.0","error":

,"id":5}

btw, all these issues aren't directly affecting the fix, so they could be split out in a separate issue so that the actual fix can be merged - would that be ok ?

1. fixed
2.1. created followup issue for entity referencing at ZBX-3276;
2.2. then maybe we can just remove "You", making the message start with "Cannot delete..."
2.3. what about this one ?
3. & 4. created followup issue for api problems at ZBX-3277

left for this issue : 2.2. + 2.3. code review, good to merge otherwise

Error strings changed, code reviewed by Alexei

good to merge

Merged: branches/1.8 16097