Added simple url conflict checks, refs #1878

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | ---
| Fixed tickets | ---
| Refs tickets  | #1878
| License       | MIT
| Doc PR        | ---
Right. When I added the conflict checks, I noticed that the
parent handleCommand method in some cases does a redirect and exits
execution, therefore the code here wasn't executed at all.