jruby prompt adding chars?

[mooreniemi]

in pry (using a custom prompt), i see it add up to 4 chars. for instance, if i type "foodler", hit enter, then up arrow to retype, "food" will be caught in the prompt. if i press enter, it will clear the cursor back to the actual prompt end. i've talked to the pry guys and i'm not 100% sure it isn't an issue there, but i hoped you could help lead me to a fix.

in vanilla irb (no custom config, nothing), i see slightly different (but maybe related?) behavior, when i hit return on an empty line, chars will be added to the subsequent line and however many times i press enter, those extra chars will remain. if i type something in and hit enter, the cursor will return to the proper spacing from the prompt.

[DavidEGrayson]

If the JRuby verison number in your IRB screenshot is accurate, you are using a pretty old version. I think you should try out 9.0.0.0-pre1 to see if the problem was already fixed.

I can't reproduce the IRB problem using JRuby 9.0.0.0-pre1 in Windows.

[mooreniemi]

the pry prompt is still an issue in 1.7.10 and 1.7.13, fwiw. but the other cursor handling issue (second one) -- youre right, appears to be resolved in 1.7.10 +. i'll bark at the pry guys :)

[headius]

Pry may be expecting more out of the readline Ruby stdlib than we're able to provide, or else that lib under Windows has some issues. I assume this doesn't happen on non-Windows?

Also, if we are working correctly in 9k.pre1 perhaps there's something to backport, but the priority of fixing in 1.7.x is somewhat reduced in my mind.

[kyrylo]

I was able to reproduce this bug with Pry 0.10.1 (the latest version) and JRuby 9.0.0.0.pre1 on Linux, using this prompt.

The same version of Pry doesn't feature this bug on CRuby 2.2.0. Perhaps, because CRuby's readline supports RL_PROMPT_START_IGNORE and RL_PROMPT_END_IGNORE.