SUMMARY:

When first clicking the "Custom" command link in the Configure Fields popup of the Create Issue dialog, only a subset of the listed components are selected by default. Clicking elsewhere to dismiss the popup treats the selected subset like a requested GUI change and modifies the underlying modal dialog.

DETAILS:

Even with a newly created user:

On first view of the "Create Issue" screen, all expected fields are visible. But if you click on the "Configure Fields" dropdown and simply select the "Custom" command link, some fields are ticked by default and others are not.

As a result, a user who clicks the picklist to see what it is, and then clicks Custom, and then clicks the modal dialog to dismiss the popup without making deliberate changes may involuntarily, and unexpectedly, have gui components removed from the Create Issue screen (and have that screen revision persisted) by that operation.

SOLUTION:

Clicking the "Custom" command link should not only list all relevant (i.e., currently visible) components in the popup, but should show them all as selected by default. Only explicitly unticking a box should deselect a component that was visible when the popup was invoked.