When you have a selection that spans multiple lines, and the first line that's selected consists only of the newline character at the end, the
unindent command does not behave as expected.
I attached a screenshot of the selection that I'm describing. I would expect the
unindent command to outdent these three lines, but what actually happens is that it outdents the first and third lines, but not the second.
This same selection works fine for the
indent command, for some reason.