[Bug 1417904] [NEW] terminal settings messed up after do-release-upgrade run less for you

[Peter Cordes]

Public bug reported:

14.04 -> 14.10 went flawlessly, on my nearly-default-install laptop.

The only problem I noticed was when prompted to yN or d for details.
After hitting d, return, then exitting from less (without doing anything
weird like ^z), the prompt for what to do next wasn't printed.  I think
somehow the process printing it started line buffering instead of doing
unbuffered i/o, because when I did press y, I saw multiple prompts all
on the same line.  (I think.  They linewrapped, and scrolled away
quickly.  I should have hit ^space [ to enter screen's copy/paste mode,
where scrolling is prevented (tty output blocks once the buffer fills
up.  I love that do-release-upgrade automatically run itself in a screen
session.)

 I reproduced it on my desktop (still running 14.04 for now), too.  I
only had to go as far as having 'do-release-upgrade -d' comment-out all
my PPAs in sources.list (which it puts back when you say N to cancel),
and download some lists, before the first yN/ [d]etails prompt.

tty echo is still enabled.  The less status-line prompt disappears,
leaving the last line of the screen empty until you type anything.

The laptop (amd64) ran sudo do-release-upgrade -d from a gnome-terminal
tab, running under a stock Ubuntu Gnome desktop.

The desktop (amd64) ran sudo do-release-upgrade -d from a screen session
in a gnome-terminal tab, in a fluxbox session.

LANG=en_CA.UTF-8 on the laptop, en_CA.utf8 on the desktop.

copy-pasted from my gnome-terminal after reproducing the bug and
pressing return a few times before N<return>:


...
  libunwind-dev libva-drm1 libvisio-0.1-1 libvlccore8 libvncclient0
  libwireshark5 libwiretap4 libwpd-0.10-10 libwpg-0.3-3 libwps-0.3-3
  libwsutil4 libx32asan1 libx32cilkrts5 libx32gcc-4.9-dev
  libx32stdc++-4.9-dev libx32ubsan0 libxcb-xkb1 libxkbcommon-x11-0



N
Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]
Restoring original system state

Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
Building data structures... Done
=== Command terminated with exit status 1 (Wed Feb  4 03:28:41 2015) ===

** Affects: ubuntu-release-upgrader (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to ubuntu-release-upgrader in
Ubuntu.
https://bugs.launchpad.net/bugs/1417904

Title:
  terminal settings messed up after do-release-upgrade run less for you

Status in ubuntu-release-upgrader package in Ubuntu:
  New

Bug description:
  14.04 -> 14.10 went flawlessly, on my nearly-default-install laptop.

  The only problem I noticed was when prompted to yN or d for details.
  After hitting d, return, then exitting from less (without doing
  anything weird like ^z), the prompt for what to do next wasn't
  printed.  I think somehow the process printing it started line
  buffering instead of doing unbuffered i/o, because when I did press y,
  I saw multiple prompts all on the same line.  (I think.  They
  linewrapped, and scrolled away quickly.  I should have hit ^space [ to
  enter screen's copy/paste mode, where scrolling is prevented (tty
  output blocks once the buffer fills up.  I love that do-release-
  upgrade automatically run itself in a screen session.)

   I reproduced it on my desktop (still running 14.04 for now), too.  I
  only had to go as far as having 'do-release-upgrade -d' comment-out
  all my PPAs in sources.list (which it puts back when you say N to
  cancel), and download some lists, before the first yN/ [d]etails
  prompt.

  tty echo is still enabled.  The less status-line prompt disappears,
  leaving the last line of the screen empty until you type anything.

  The laptop (amd64) ran sudo do-release-upgrade -d from a gnome-
  terminal tab, running under a stock Ubuntu Gnome desktop.

  The desktop (amd64) ran sudo do-release-upgrade -d from a screen
  session in a gnome-terminal tab, in a fluxbox session.

  LANG=en_CA.UTF-8 on the laptop, en_CA.utf8 on the desktop.

  copy-pasted from my gnome-terminal after reproducing the bug and
  pressing return a few times before N<return>:


  ...
    libunwind-dev libva-drm1 libvisio-0.1-1 libvlccore8 libvncclient0
    libwireshark5 libwiretap4 libwpd-0.10-10 libwpg-0.3-3 libwps-0.3-3
    libwsutil4 libx32asan1 libx32cilkrts5 libx32gcc-4.9-dev
    libx32stdc++-4.9-dev libx32ubsan0 libxcb-xkb1 libxkbcommon-x11-0



  
  N
  Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]Continue [yN]  Details [d]
  Restoring original system state

  Aborting
  Reading package lists... Done
  Building dependency tree
  Reading state information... Done
  Building data structures... Done
  === Command terminated with exit status 1 (Wed Feb  4 03:28:41 2015) ===

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1417904/+subscriptions