Bug #14691: ANSI Erase in Line not working properly in Windows

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.5.1p57 (2018-03-29 revision 63029) [x64-mingw32]
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN

[rsranger65 (Alex Gittemeier)]

When I run the following commands in either the Windows 10 Command Prompt

ruby -e 'puts "Hello world!\e[D\e[D\e[K\nWhat is up?"'
ruby -e 'puts "Hello world!\e[D\e[D\e[0K\nWhat is up?"'
ruby -e 'puts "Hello world!\e[D\e[D\e[1K\nWhat is up?"'

I expect to get the same output as from:

printf "Hello world!\\e[D\\e[D\\e[K\nWhats up?\n"
printf "Hello world!\\e[D\\e[D\\e[0K\nWhats up?\n"
printf "Hello world!\\e[D\\e[D\\e[1K\nWhats up?\n"

Which is:

Hello worl
Whats up?
Hello worl
Whats up?
           !
Whats up?

But instead I get:

          d!
What is up?
          d!
What is up?
          d!
What is up?

The same behavior occurs in PowerShell as well, with appropriate changes to escaping (escaping the double quotes in the ruby code).

It appears that for the CSI [n] K sequences, n=0 (the default) and n=1 are doing the same operation and that n=1 has an off by one error

Windows version: Version 10.0.16299 Build 16299

[shevegen (Robert A. Heiler)]

has an off by one error

It's always these two major problems in the fields of computer and programming:

• Giving something a good name (see matz's recent comment on a matz bot AI rejecting not ideal names for an API)
• Simplicity versus Complexity in general
• Off by one errors

:D

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r63187.

---

win32.c: fix CSI sequences to delete

• win32/win32.c (constat_apply): CSI 'J' and 'K' are defaulted to
  1, not 0. [ruby-core:86560] [Bug #14691]

• win32/win32.c (constat_apply): "delete before cursor" sequences
  include the cursor position.