"Line by line difference" of config files during release upgrade is an unreadable mess

[teo1978]

I upgraded from 16.04 to 18.04, then to 19.10, then to 20.04.

I'm not sure ini whih of the upgrades I noticed the issue but I'm pretty sure it applies to all of them.

As usual, the upgrade had to install some configuration files which would replace some files I had modified, and so I got the prompt to choose what to do: whether to keep my modified version, or overwrite it with the packager's version.

I don't remember the exact interface, but when you are prompted to choose that, you have a few options to see the differences between the two files. I think by default it shows a classical diff (with "+++"s and "---"s) but there is an option to show "line by line differences".

I chose that for one file, and I expected to see a side-by-side diff similar to those I've seen in dozens of tools, where you see the two entire files side by side and the differences are highlighted in both sides in colors, such as lines that are added or removed and lines that are modified.

Short of that, the very least that I would have expected was to show the two files side by side.

Instead, this PATHETIC CRAP showed up which can be seen in the sceenshot.
And don't remind me of the code of conduct. I'm not insulting anybody. It's a FACT that this is crap and that it is pathetic.

Not only are DIFFERENCES not shown (line by line or otherwise). The two files are shown as one single text file, where each line of the second file is just appended to the corresponding line of the first file.
You can't even tell where the line of one file begins and the line of the other ends.

It's a completely useless way to show "differences" between two files. It's less useful than just showing the two files next to each other in two independent text boxes. Way less useful. Let alone compared to an actual side-by-side diff tool (and there are plenty to chose from).

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: apt 2.0.2ubuntu0.1
ProcVersionSignature: Ubuntu 5.4.0-40.44-generic 5.4.44
Uname: Linux 5.4.0-40-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.20.11-0ubuntu27.3
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: X-Cinnamon
Date: Sat Jul 18 17:30:36 2020
InstallationDate: Installed on 2013-10-11 (2471 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
SourcePackage: apt
UpgradeStatus: Upgraded to focal on 2020-07-12 (5 days ago)

[Colin Watson (cjwatson)]

You've already been reminded of the code of conduct, but you continue to violate it; it's perfectly possible to point out deficiencies in software in a constructive and respectful way, which "pathetic crap" is not. Since it doesn't appear that you intend to change your behaviour, I'll be suspending your Launchpad account shortly (once this bug notification has been sent).

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Julian Andres Klode (juliank)]

Certainly not an apt bug. Feature request for like debconf, UCF, and dpkg? Or packagekit? Don't know