Merge lp:~osomon/ubuntu-wallpapers/readme into lp:ubuntu-wallpapers

[Olivier Tilloy]

Add detailed instructions on how to add wallpapers for a new Ubuntu release.

[Iain Lane (laney)]

Thanks Olivier. Just one suggestion inline, then please merge. This is great ♥

review: Needs Fixing

[Sebastien Bacher (seb128)]

Thanks for working on that Olivier, the instructions are clear to me, +1 also for merging once the comment from Laney is resolved

review: Approve

[lp:~osomon/ubuntu-wallpapers/readme]

786. By Olivier Tilloy on 2021-07-06

Clarify the changes to debian/control.

=== renamed file 'README' => 'README.md'
--- README	2007-09-19 14:48:45 +0000
+++ README.md	2021-07-06 16:14:27 +0000
@@ -0,0 +1,85 @@
+# How to add wallpapers for a new Ubuntu release
+
+## Before starting
+
+It is good practice to file a bug in Launchpad to track the addition of the wallpapers for a new Ubuntu release, against the ubuntu-wallpapers source package.
+This bug will be referenced in the changelog entry as well as in the VCS revision history.
+See e.g. https://bugs.launchpad.net/ubuntu/+source/ubuntu-wallpapers/+bug/1921139.
+
+## Sources
+
+Wallpapers typically come from two sources:
+  * the Canonical design team will provide the official wallpaper (and a greyscale variant)
+  * a selection of community-provided pictures (see https://wiki.ubuntu.com/UbuntuFreeCultureShowcase for details)
+
+## Scripts and pre-requisites
+
+There are scripts in the `scripts/` directory that partially automate the task of adding wallpapers for a new Ubuntu release. Some of these scripts assume they are being run on the target release (they call `lsb_release`), so make sure you fulfill that requirement, or you will need to hand-edit generated files (alternatively export `$LSB_OS_RELEASE` to point to a file that overwrites your host system's `/usr/lib/os-release` with the values corresponding to the new release that wallpapers are being generated for − that file is installed by the `base-files` package).
+
+Some of these scripts assume that the community-provided wallpapers are named following this convention:
+
+    SUBJECT_by_AUTHOR.EXTENSION
+
+where SUBJECT and AUTHOR may be made up several words, either dash (-) or underscore (_) separated, and EXTENSION may either be "jpg" or "png".
+
+## Disclaimer
+
+At the time of writing, this is still largely a manual (and as such, error-prone) process. A good goal would be to automate it as much as possible.
+
+## Step-by-step instructions
+
+ 0) `export CODENAME=$(lsb_release -cs)`
+
+1a) get the new official wallpaper and replace the existing `warty-final-ubuntu.png` with it
+1b) get the new greyscale official wallpaper and copy it at the root of this branch
+1c) get the community wallpapers for the upcoming Ubuntu release (codenamed `$CODENAME`) and unpack them in a staging subfolder (e.g. named `staging/`) inside this branch
+
+ 2) create `$CODENAME-wallpapers.xml.in` (which references only the community wallpapers):
+
+        cd staging
+        ../scripts/generate-xml.sh > ../$CODENAME-wallpapers.xml.in
+        cd ..
+
+ 3) now copy the greyscale official wallpaper to the `staging/` directory
+
+ 4) create `contest/$CODENAME.xml` (which references both the community wallpapers and the greyscale official one):
+
+        cd staging
+        ../scripts/update-background.py > ../contest/$CODENAME.xml
+        cd ..
+
+ 5) create `debian/ubuntu-wallpapers-$CODENAME.install` listing all relevant files:
+
+        INSTALL_FILE=debian/ubuntu-wallpapers-$CODENAME.install
+        for i in $(ls staging); do echo usr/share/backgrounds/$i >> $INSTALL_FILE; done
+        echo usr/share/gnome-background-properties/$CODENAME-wallpapers.xml >> $INSTALL_FILE
+        echo usr/share/backgrounds/contest/$CODENAME.xml >> $INSTALL_FILE
+
+ 6) move all the files from the staging folder to the root of the branch, and delete the empty folder:
+
+        mv staging/* ./
+        rmdir staging
+
+ 7) update `po/POTFILES.in`:
+
+        echo $CODENAME-wallpapers.xml.in | sort -m po/POTFILES.in - > po/POTFILES.in.new
+        mv po/POTFILES.in.new po/POTFILES.in
+
+ 8) update the translation template (`po/ubuntu-wallpapers.pot`):
+
+        cd po
+        intltool-update -p -g ubuntu-wallpapers
+        cd ..
+
+ 9) update `debian/ubuntu-wallpapers.links` to change the target of the ubuntu-default-greyscale-wallpaper.png symlink
+
+10) update `debian/control`:
+    * add a new package at the end of the file named `ubuntu-wallpapers-$CODENAME`
+    * make `ubuntu-wallpapers` depend on `ubuntu-wallpapers-$CODENAME` (and remove the dependency on the previous version)
+    * add the previous version to the `Suggests` section
+
+11) update `debian/copyright` to add all the new wallpapers (community and greyscale official background) and their authors under the corresponding `License` block
+
+12) add a new `debian/changelog` entry referencing the Launchpad bug number by running `dch -v $(lsb_release -sr).1-0ubuntu1`
+
+Once this is done, don't forget to add new files to the VCS and commit using the `debian/changelog` entry and linking to the Launchpad bug (use `bzr commit --fixes="lp:NNNNNN"`).