Nano 4.6 eats this line

[Seb]

Hello,


I have stumbled upon what seems to be a bug in Nano 4.6 (no patch 
applied). Please find attached a one-line example file. When it is opened 
in an 80-column terminal (be it XTerm or URXvt),

* pressing <Tab> at the beginning of the line (or when the cursor is on
  the first letter, "p") makes the line disappear;

* adding a character anywhere on the line except on the first column
  makes the line disappear.

These symptoms do not appear when the file is opened with Nano 3.2 (from 
Debian stable).

The example is not minimal. Some letters can be removed from the end of 
the line and the behavior remains the same. But if too many characters are 
removed, the behavior becomes normal.

During the course of my tries, with simple adding/removing of characters I 
once crashed Nano, which also made the terminal criss-crossed with lines 
of text; I typed "reset" before I could think of making a screen capture.

The characters on this line are from a TeX file (which I was writing when 
I noticed the bug); they are all from the ASCII set; my locale est latin1.

Can you reproduce and confirm the bug?


Kind regards,
Sébastien.

example
Description: Text document