[1.55][Ssp/smp] Visual Bug With "lua" Program

A lot of the time I use the standard lua program to test lines of code before I add them to my programs. Lately, I've noticed that when I use long commands (or sets of commands) that run off the screen, if I scroll back near the beginning and then to the end again, the last letter duplicates. For example:
I type:

for k,v in pairs(peripheral.getMethods("right")) do print(v) end

Say I realized that I mistyped something, so I then scroll back to it and fix it. If I then scroll back to the end, I get this:

for k,v in pairs(peripheral.getMethods("right")) do print(v) endd

However when I run the command, it runs fine, as if that extra "d" didn't exist.
I am fairly sure that this s simply a visual bug, but I thought I'd post it anyways.

Please search before posting a bug. This is a known bug, and it's been reported multiple times, eg. here and here.

It's not so much of a bug as much as an oversight in the lua program. It's not likely to be fixed soon, as it's only a cosmetic change, and it's been reported quite some time ago.