CRM-21300: Addressed notices due to unexpected NULL from Joomla DB object.

[universalhandle]

Overview

Prevent notices described in CRM-21300 from being raised.

Before

See CRM-21300.

After

No more notices or warnings (needs validation).

Technical Details

The Joomla DB object returns NULL in some cases, which was not immediately obvious from the documentation. This PR ensures that the DBO-wrapping method always has a consistent return type.

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• CRM-21300: Joomla: Trying to get property of non-object in CRM/Core/Permission/Joomla.php

[universalhandle]

@totten, I haven't actually run this code, but it should address the warnings/notices you reported, all of which seem to follow on the original unexpected return type. Could you please validate?

[seamuslee001]

@mattwire can you take a look at this and see if this would change anything on your joomla site?

[eileenmcnaughton]

@GinkgoFJG can you put this against 4.7.27rc- as a recent regression this should go in the rc

[eileenmcnaughton]

Also the calling function looks like

    $associations = $this->getUserGroupPermsAssociations();
    $cmsPermsHaveGoneStale = FALSE;
    foreach (array_keys(get_object_vars($associations)) as $permName) {

so we shouldn't return an array if null unless we also return an array if successful (which is probably the cleanest - ie. pass TRUE as the second param to json_decode

[universalhandle]

We are not returning an array in the case of a failed query; we are returning an object with no properties. The json_decode() call returns an object of type stdClass (because that is how Joomla stores the permissions data). I think this is cleanest/safest because:

• with this change, getUserGroupPermsAssociations() returns a stdClass object no matter what
• get_object_vars($associations) will return an empty array in the case of a failed query, effectively short-circuiting the foreach loop

[universalhandle]

@eileenmcnaughton: I've rebased against 4.7.27-rc and changed the base of the PR.

[mattwire]

@GinkgoFJG @seamuslee001 I'll try out later on a Joomla 3.8.1 site. Haven't seen any warnings/notices though so I guess I'm just looking for "it still seems to work"!

[mattwire]

Ok no adverse affects - seems ok to me!

[eileenmcnaughton]

test this please

[seamuslee001]

This looks good to me. Code looks safe, this has passed Jenkins and has been tested by Matt on a Joomla install with no errors showing up. I think this is good to merge. Note i haven't personally tested the code but it make sense to me and agree with Franks's comments re the stdObject

[totten]

Nice, @GinkgoFJG !

There are multiple supportive comments. Also, I can confirm that this resolves the warnings on my workstation when installing from an extracted .zip on Joomla 3.6.

Merging.