cursor mode does not behave as expected when word-wrapping is enabled

[RsrnlWysxr]

lnav version
v0.12.2 is the latest

Describe the bug
When I use cursor mode and enable word-wrapping, moving the cursor to the last line (by pressing the 'G' key twice), the cursor fails to update correctly when the log is refreshed and screen stop refresh.

To Reproduce
Steps to reproduce the behavior:

1. lnav l.log

2. hotkey: ctrl-w, to enalbe wrod-wrapping
3. double hotkey: G, to move to the last line

[RsrnlWysxr]

To be precise, after the first line break logic occurs, the cursor updates to that line, and thereafter, the cursor will no longer update.