Currently a FlatpakTransaction object only operates on one installation,
but uses others (by default the system installations) for dependencies
such as runtimes. In addition to checking those dependency installations
for runtimes we check their configured remotes when deciding whether to
add a new remote as an origin for a flatpakref or as a runtime remote
for a flatpakref. This commit changes the behavior so that we only check
the installation being operated on to find out if a remote already
exists. This is the correct behavior in both cases: the origin remote
and the runtime remote. Otherwise the installation can error out when it
fails to find the runtime, or it can fail to respect the
SuggestRemoteName key which is supposed to dictate the name for the
origin remote.
One side effect of this is that a remote might be duplicated in the user
installation which already exists in the system installation, even if
the runtime it provides is already installed. But if you don't want
remotes in multiple installations you can just stick to using one
installation consistently.
Also, add a unit test for this in testlibrary.c (which required a bit of
refactoring).
Fixes https://github.com/flatpak/flatpak/issues/2758Closes: #2761
Approved by: alexlarsson
3cbad4369d