compose: Do not compose the look-up path twice

[aleixpol]

I could see the source target appearing twice and then the algorithm eventually bailing out. We were building the path twice.

G_MESSAGES_DEBUG=all
appstreamcli compose --components=org.kde.Platform --origin=org.kde.Platform /tmp

[aleixpol]

$ 
<atform --result-root=/buildstream-install --data-dir /buildstream-install/usr/share/app-info/xmls --origin=org.kde.Platform  /buildstream-install --verbose
** (appstreamcli:262): DEBUG: 11:42:59.042: run appstreamcli: compose
Only accepting component: org.kde.Platform
Processing directory: /buildstream-install
Composing metadata...
** (appstreamcli-compose:262): DEBUG: 11:42:59.052: No media export directory set, but icon 128x128@1 is set for remote delivery. Disabling remote for this icon type.
** (appstreamcli-compose:262): DEBUG: 11:42:59.052: No media export directory set, but icon 128x128@2 is set for remote delivery. Disabling remote for this icon type.
** (appstreamcli-compose:262): DEBUG: 11:42:59.052: No media export directory set, but screenshots are supposed to be stored. Disabling screenshot storage.
** (appstreamcli-compose:262): DEBUG: 11:42:59.052: Will use temporary directory '/tmp/as-compose_c0Bqn1' and delete it after this run.
** (appstreamcli-compose:262): DEBUG: 11:42:59.053: Creating contents index for directory: /buildstream-install
** (appstreamcli-compose:262): DEBUG: 11:42:59.053: Indexing location: /buildstream-install/buildstream-install/usr/share

** (appstreamcli-compose:262): DEBUG: 11:42:59.053: Index done for directory: /buildstream-install
** (appstreamcli-compose:262): DEBUG: 11:42:59.053: Looking for metainfo files in: /usr/share/metainfo

Emphasis on the "indexed location" line.

[ximion]

Which version of AppStream is this? Does indeed look odd...

[aleixpol]

I could reproduce this issue both on master and the one in freedesktop-sdk from 25.08. That said, I was given a different call to initialise it and it seems to work.

Maybe we just need some input sanitisation?

https://gitlab.com/freedesktop-sdk/flatpak-kde-runtime/-/merge_requests/7#note_2819751947

[ximion]

Oh, from that command, I think you might be using the tool wrong. prefix is literally just the prefix below the input directory, so, /usr or /usr/local. It must not include a path outside of the directory unit, so passing it any absolute path to the outside is certainly wrong.

So I also think this patch is wrong. You need to figure out what you set as prefix for the buildsystem (Meson, Automake, CMake, etc.) and pass that path as prefix. Then just point compose at all the directories it should look into for data (as positional arguments).