Issue2275

Nothing happens when I try to type backslash to Jython console on Windows. FWIW, I'm using Finnish locale.

No problem for US locale on Windows 8.1, OS X 10.10.2, or Ubuntu 14.10, so that's interesting. Need to investigate further.

Typing backslash works fine on Linux for me too. Windows is Win7 on Virtual Box although I doubt that matters too much. Typing backslashes worked fine with earlier Jython versions and still works with CPython and IronPython.

So maybe this is a Windows 7 specific issue, or a problem on a specific code page?

Doesn't seem to be related to the code page but to the locale. With Finnish locale we use code page 850 but changing it to 437 using `chcp` had no effect. Changing locale from FI to EN resolved the problem (after I found out which key to press to get the backslash).

With Finnish keyword layout you get the backslash by pressing AltGr and the key one right from the 0 key (we have '+' there, in US layout it apparently is '-'). I figured AltGr could have something to do with the problem and did some experimenting with other keys requiring it:

- All these work fine: '$', '{', '}', '|'.
- Instead of '£' I get 'ú'.
- Getting '[' requires pressing it twice.
- Getting ']' requires first pressing '[' and then ']'.
- Getting '@' also requires first pressing '[' and then '@'.
- I actually get '\' too by first pressing '[' and then '\'!

Looks like we have identified the problem then, and it's the same one as this open issue with JLine2 - https://github.com/jline/jline2/issues/156 - also AltGr. But AltGr does not appear on US keyboards, so that's probably why we are seeing it as an issue - the usual internationalization problems!

Good intro to the topic in http://en.wikipedia.org/wiki/AltGr_key

We most likely will have to fix JLine2 to fix this problem.

Although the JLine2 bug is still open, I noticed that the linked Scala bug (https://issues.scala-lang.org/browse/SI-8759) has been closed out due to a fix in JLine 2.12.1, released last month (http://mvnrepository.com/artifact/jline/jline/2.12.1)

We should update accordingly.

I tested JLine 2.12.1 by starting Jython like

    jython -J-Xbootclasspath/p:jline-2.12.1.jar

and was able to type the backslash just fine. I got some weird tracebacks before Jython actually started, but that is likely due to using -Xbootclasspath.

Tracebacks must be due to the use of boot classpath, but that's a good way to test without modifying build.xml.

JLine upgraded to 2.12.1 as of https://hg.python.org/jython/rev/e050becb7e28

I confirmed that it works (on a Finnish locale system).