remove command can fail for addons, contains possible infinite loop

[Chris Lasher]

SRU Impact statement:

The Ruby script addon-manager.rb contains an error in the code for the remove command. This bug causes certain addons where the ~/.vim directory is actually a symbolic link to another directory. This is the case for the Vim R plugin, distributed as a Debian package here:

http://sites.google.com/site/jalvesaq/vimrplugin

Removal will fail because it attempts to invoke a rmdir on the symbolically-linked ~/.vim file, which causes a Ruby exception.

Patch / Resolution:

The problem is that the while-loop on line 66 is written "while paths.size", which, in Ruby, will always evaluate to be true, because even the value "0" is considered true in Ruby. See:

http://ruby-doc.org/docs/Newcomers/ruby.html#boolean

Were it not for a fluke exception-handling within the loop, and exception raising in the case when the ~/.vim directory is a symbolic link, this would actually result in an infinite-loop. The loop should be changed to "while paths.size > 0".

The fixed version is already available in Oneiric (0.4.3ubuntu1), and the patch has been forwarded to Debian.

Patch for natty-proposed: https://bugs.launchpad.net/ubuntu/lucid/+source/vim-addon-manager/+bug/802036/+attachment/2221173/+files/vim-addon-manager_0.4.3ubuntu0.11.04.0.debdiff
Patch for maverick-proposed: https://bugs.launchpad.net/ubuntu/lucid/+source/vim-addon-manager/+bug/802036/+attachment/2221174/+files/vim-addon-manager_0.4.3ubuntu0.10.10.0.debdiff
Patch for lucid-proposed: https://bugs.launchpad.net/ubuntu/lucid/+source/vim-addon-manager/+bug/802036/+attachment/2221175/+files/vim-addon-manager_0.4.3ubuntu0.10.04.0.debdiff

TEST CASE:

Steps to reproduce the behavior:
1) Install vim-addon-manager
2) Install the Vim R plugin DEB package from http://sites.google.com/site/jalvesaq/vimrplugin
3) Move the ~/.vim folder to another location, such as ~/vimbak
4) Create a temporary folder ~/tmpvim
5) Create a symbolic link with "ln -s ~/tmpvim ~/.vim"
6) Run "vim-addons install r-plugin"
7) Run "vim-addons remove r-plugin"
8) Observe an error message like the following

Info: removing installed addon 'r-plugin' from /home/chris/.vim
/usr/lib/ruby/1.8/fileutils.rb:264:in `rmdir': Not a directory - /home/chris/.vim (Errno::ENOTDIR)
 from /usr/lib/ruby/1.8/fileutils.rb:264:in `rmdir'
 from /usr/lib/ruby/1.8/fileutils.rb:263:in `each'
 from /usr/lib/ruby/1.8/fileutils.rb:263:in `rmdir'
 from /usr/lib/ruby/1.8/vim/addon-manager.rb:68:in `remove'
 from /usr/lib/ruby/1.8/set.rb:194:in `each'
 from /usr/lib/ruby/1.8/set.rb:194:in `each_key'
 from /usr/lib/ruby/1.8/set.rb:194:in `each'
 from /usr/lib/ruby/1.8/vim/addon-manager.rb:80:in `remove'
 from /usr/lib/ruby/1.8/vim/addon-manager.rb:75:in `each'
 from /usr/lib/ruby/1.8/vim/addon-manager.rb:75:in `remove'
 from /usr/bin/vim-addons:264:in `send'
 from /usr/bin/vim-addons:264

Regression risk:

Slim to none. The patch does not affect other code paths.

From the original bug description:

This bug affects the upstream Debian package of vim-addon-manager, too.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: vim-addon-manager 0.4.3
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
NonfreeKernelModules: nvidia wl
Architecture: amd64
Date: Sat Jun 25 16:24:17 2011
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
PackageArchitecture: all
ProcEnviron:
 LC_TIME=en_DK.UTF-8
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: vim-addon-manager
UpgradeStatus: Upgraded to natty on 2011-04-30 (56 days ago)

[Chris Lasher (chris.lasher)]

Here is a patch that should be applied to the file addon-manager.rb

The patch fixes the errant while-loop.

[Launchpad Janitor (janitor)]

This bug was fixed in the package vim-addon-manager - 0.4.3ubuntu1

---------------
vim-addon-manager (0.4.3ubuntu1) oneiric; urgency=low

  * Apply patch from Chris Lasher fixing incorrect handling
    in the remove command for ~/.vim being a symlink. Thanks,
    Chris! (LP: #802036)
 -- Daniel T Chen <email address hidden> Mon, 18 Jul 2011 16:52:11 -0400

[Clint Byrum (clint-fewbar)]

Hello Chris, or anyone else affected,

Accepted vim-addon-manager into natty-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Clint Byrum (clint-fewbar)]

Hello Chris, or anyone else affected,

Accepted vim-addon-manager into maverick-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Clint Byrum (clint-fewbar)]

Hello Chris, or anyone else affected,

Accepted vim-addon-manager into lucid-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Ubuntu Foundations Team Bug Bot (crichton)]

The fix for the this bug has been awaiting testing feedback in the -proposed repository for lucid for more than 90 days. Please test this fix and update the bug appropriately with the results. In the event that the fix for this bug is still not verified 15 days from now the package will be removed from the -proposed repository.

[Brian Murray (brian-murray)]

The version of vim-addon-manager in lucid-proposed has been removed as this bug report was not verified in a timely fashion.

[Rolf Leggewie (r0lf)]

lucid has seen the end of its life and is no longer receiving any updates. Marking the lucid task for this ticket as "Won't Fix".