Currently the Git plugin has this 'weird' behavior where by, when someone navigates to changeset details on the Jenkins dashboard the changeset information is parsed to pull out user information for each commit and if one or more of those users don't have user profiles in Jenkins new ones are created for them on the fly automatically.

This automatic behavior has the unfortunate side effect of causing redundant, superfluous user profiles to be created on Jenkins which is confusing at best and fragile at worst. For example, suppose a user logs in to the Jenkins dashboard authenticating via LDAP or AD - they will get a user profile created. Then suppose they commit some changes to Git and their Git client / profile has a slightly different configuration from their LDAP profile (ie: maybe their user name is slightly different). Then when someone browses for those changesets on the Jenkins dashboard a second user profile gets magically created with a very similar name to the first - sometimes with overlapping / duplicated metadata in each. Heaven forbid that the same user then has several different repositories or systems they do work on, each potentially with slightly different user names on them, each of which will produce even more redundant copies of Jenkins users magically behind the scenes.

To make matters worse, any other Jenkins plugins that make use of these superfluous user profiles ends up producing different results depending on which user profile they decide to choose for any particular operation. Plugins such as the Claim broken build plugin offer very obvious examples of how this causes no end of confusion. Since this plugin allows the user to select a Jenkins user name from a drop down list, and this list shows the "display name" for every user ... and the display name may be duplicated between these user profiles, it becomes impossible to ensure you are selecting the correct one.

As such I would like to see a simple check-box under the Manage Jenkins dashboard which, when unchecked, simply stops the Git plugin from automatically creating users on the Jenkins master. To preserve backwards compatibility this option could be disabled by default if desired. The option would probably fit with the "Create new accounts base on author/committer's email" under the general configuration page.