Update-manager list earlier changes for certain packages before the relevant change for the update in question

[Hans Joachim Desserud]

Steps to reproduce:
1. Have an old version of some boost package when a newer version is available.
2. Open update-manager, select the boost package and look at the "Changes" tab.

Expected result:
The tab should contain which version I have currently installed, which version is available, and a section from the changelog summarizing the changes between those two versions.

Actual result:
While the boost packages have this, it is far down below a series of older changelog entries. All of these are for versions older than the one currently installed and as such are already included in the version I have. Furthermore they push down the "currently installed/available version" part which should always be listed at the top.

I am not sure why this happens, and why it only happens with boost packages. I have seen this before with a previous boost update (unfortunately I failed to file a bug before updating), but not in any other packages.

$ apt-cache policy libboost-date-time1.49.0
libboost-date-time1.49.0:
  Installed: 1.49.0-3.1ubuntu1.1
  Candidate: 1.49.0-3.1ubuntu1.2
  Version table:
     1.49.0-3.1ubuntu1.2 0
        500 http://no.archive.ubuntu.com/ubuntu/ quantal-updates/main i386 Packages
        500 http://security.ubuntu.com/ubuntu/ quantal-security/main i386 Packages
 *** 1.49.0-3.1ubuntu1.1 0
        100 /var/lib/dpkg/status
     1.49.0-3.1ubuntu1 0
        500 http://no.archive.ubuntu.com/ubuntu/ quantal/main i386 Packages

With the package above installed, this issue should be easy to reproduce. I have also attached the content of the "Changes" tab in update-manager.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: update-manager 1:0.174.4
ProcVersionSignature: Ubuntu 3.5.0-23.35-generic 3.5.7.2
Uname: Linux 3.5.0-23-generic i686
ApportVersion: 2.6.1-0ubuntu10
Architecture: i386
Date: Sun Feb 24 15:04:06 2013
GsettingsChanges:
 b'com.ubuntu.update-manager' b'first-run' b'false'
 b'com.ubuntu.update-manager' b'launch-time' b'1361714262'
 b'com.ubuntu.update-manager' b'show-details' b'true'
 b'com.ubuntu.update-manager' b'window-height' b'744'
 b'com.ubuntu.update-manager' b'window-width' b'959'
InstallationDate: Installed on 2012-10-20 (127 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release i386 (20121017.2)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: No upgrade log present (probably fresh install)

[Hans Joachim Desserud (hjd)]

I have seen this a couple of more times over the years, but I recently caught the same issue with chromium-browser. This is on 20.04, according to `apt policy` the changes are

$ apt policy chromium-browser
chromium-browser:
  Installert: 83.0.4103.61-0ubuntu0.18.04.1
  Kandidat: 83.0.4103.97-0ubuntu0.20.04.1
  Versjonstabell:
     83.0.4103.97-0ubuntu0.20.04.1 500
        500 http://no.archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages
 *** 83.0.4103.61-0ubuntu0.18.04.1 100
        100 /var/lib/dpkg/status
     80.0.3987.163-0ubuntu1 500
        500 http://no.archive.ubuntu.com/ubuntu focal/universe amd64 Packages

However, the attached log is what update-manager display under technical details -> changes. It seems to be the complete history of the chromium-browser package.

Noticing now (from the output above), could this be related to my recent upgrade from 18.04 to 20.04. In other words, when upgrading from an -updates package in one series to a package from -updates in another series the comparision is confused because the older version was newer published in the newer series and thus it doesn't have a lower bound in the changelog?

[Hans Joachim Desserud (hjd)]

Happened again with distro-info-data on Ubuntu 20.04.

$ apt policy distro-info-data
distro-info-data:
  Installert: 0.43ubuntu1.2
  Kandidat: 0.43ubuntu1.4
  Versjonstabell:
     0.43ubuntu1.4 500
        500 http://no.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        500 http://no.archive.ubuntu.com/ubuntu focal-updates/main i386 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu focal-security/main i386 Packages
 *** 0.43ubuntu1.2 100
        100 /var/lib/dpkg/status
     0.43ubuntu1 500
        500 http://no.archive.ubuntu.com/ubuntu focal/main amd64 Packages
        500 http://no.archive.ubuntu.com/ubuntu focal/main i386 Packages

As can be seen both in the output and the attached changelog from update-manager, 0.43ubuntu1.2 is currently installed and 0.43ubuntu1.4 is offered as an update. However, the changelog seem to list the complete list of changes. I do note that the entry for 0.43ubuntu1.2 is missing som without a lower bound present in the changelist it might default to showing all?

[Olivier Tilloy (osomon)]

This appears to be a bug in update-manager, where it fails to match the currently installed version against the changelog, and consequently doesn't truncate the changelog where it should, displaying the entire changelog history. I am not familiar with update-manager's code, but the code in question appears to be in the _get_changelog_or_news() function, in UpdateManager/Core/MyCache.py (https://bazaar.launchpad.net/~ubuntu-core-dev/update-manager/main/view/head:/UpdateManager/Core/MyCache.py#L210, in the 'while True' loop towards the end of the function).

[Olivier Tilloy (osomon)]

And I can reliably observe the issue in a focal VM where I installed the chromium-browser package from bionic. Update-manager offers the update to the newer version in focal, and the changelog textbox displays the entire changelog since the first version of the package.

This might be caused by the versioning scheme used to update chromium in stable releases. But it's really a bug in update-manager.