How to reproduce:
In the job configuration page add Doclinks as a post-build step, but don't add any files to publish (actually I deleted the last file item and thought this would remove the whole Doclinks post-build step).

Expected result:
The Doclinks plugin does nothing and especially doesn't claim a build failure.

Actual result:
On the web: the build is marked as failed. The console shows an error message from Doclinks, that no artifacts were found and thus causes the build to break.
Jenkins IRC Bot instead tells me, that the build passed.