Crash on PageUp + Down or PageDown + Down with short history

[selurvedu]

Prerequisites:

Your history file has to be short, so that when you invoke hstr, there should be at least two empty lines on the top.

Steps to reproduce:

1. Run hstr.
2. Press PageUp or PageDown. The topmost line will get highlighted.
3. Press Down.
4. Segmentation fault (core dumped).

Workaround:

As soon as your history becomes long enough, so there is just one empty line on the top or no empty lines at all, the segfault won't occur anymore.