isRemoveLineWhenBlank doesn't seem to work

Issue Description

The isRemoveLineWhenBlank feature should help collapse blank space, but a customer found a simple-looking scenario in which the space appeared truly empty of elements, but still wasn't collapsing.

Resolution

isRemoveLineWhenBlank can help collapse empty space no longer needed if the field from the designer is gone or blank. The blank space will not be removed if your field shares some vertical space with other report elements that are printed however. Only empty space can collapse, while elements cannot actually shrink in JR.

From the JasperReports Ultimate Guide:

In the customer's scenario they had no adjacent elements, but we found that their textField elements were overlapping by a pixel:

So technically there was a pixel of shared space or pixel of space being consumed by both the visible textfield as well as the hopefully "invisible" textfield even if it was removed via a printWhenExpression. So the resolution is to make sure your elements have not overlap of space