plone/plone.schemaeditor — pull request #5 by seanupton (2012-08-24 17:22:32+00:00)
Title: Add a constraint to ITextLineChoice['values']

Adding a constraint -- requiring all values be non-empty -- prevents multiple trailing line feeds from inducing an empty value (a term with no value), but it appears that form normalization / converter tolerates a single (and only one) trailing blankline, by ignoring it. So this constraint only catches -- in practice -- multiple trailing blank lines in the choices / vocabulary values for the field.