[Standards] Ad-hoc command error cases

Hi! While adding tests for XEP-0133: Service Administration to the XMPP Interop Testing project, we ran into trouble. Specifically, it is unclear to me how an ad-hoc command failure is to be represented. Two XEPs are relevant: - XEP-0050: Ad-Hoc Commands - XEP-0133: Service Administration I don't think either is exactly clear in the definition of non-success scenarios. XEP-0050 Section 3.6 "Commands Successful/Failed" defines: I do not believe that XEP-0050 specifies what the IQ type is (result or error) when a command execution is completed with a failure. XEP-0050 Section 4.4 "Possible Errors" defines command execution errors. All of the descriptions listed relate to conditions where the responding entity is prevented from starting to execute the command: it doesn't understand the action, the requesting entity doesn't have permissions to execute the command, and so on. In example 23, it is shown that these type of errors are used in an IQ type=error. XEP-0133 is less clear. Where errors are referenced in the descriptions of each command ("Unless an error occurs ...") they also seem to refer to scenario's where a command execution cannot start. To me, that's in line with XEP-0050. However, section 5 "Error Handling" specifies conditions that seem to are detected both _before_ but also _after_ execution of the command has started. Examples of that latter are: - <conflict/> The command cannot be completed because of a data or system conflict (e.g., a user already exists with that username). - No entity is allowed to perform the command (e.g., retrieve the CEO's roster). To me, these two are examples of what should be responded to with a <command status='completed'><note type='error'/></command>. The XEP(s) would benefit from having more explicit definitions with regards to these cases. Firstly, lets specify explicitly in XEP-0050 if a command of which the execution completed with an error is to be represented by an IQ stanza of type 'result' or 'error'. The XEP to me suggests 'result', but I don't think this is sufficiently clear from the text. For what it's worth, the implementations that I've seen (Openfire, Smack and Prosody), seem to use 'result'. Secondly, Section 5 of XEP-0133 arguably contradicts XEP-0050 - or at least adds confusion more than clarification. What added value does this section have over the error handling that is specified in XEP-0050? Perhaps referring to XEP-0133 is a good alternative to the existence of Section 5 in XEP-0133. Thirdly, the XEPs should have an example of a command that is completed-with-failure. The illustrative power of that would be very welcome. I would value your feedback on this. Kind regards, Guus