If branch is unset this is just a nicer way to set a
particular commit. However if both are set, then we verify
that the branch/tag is at that particular commit. This is
a nice way to document that we want to use a particular tag
but still protect against the tag changing or a MITM attack
modifying what that tag means.
This commit checks if <revision>:.gitmodules exists in the repo before
calling git-show on it, so an error message doesn't show up in the
program's output.
Instead of expecting the second word to be "commit", we should do like
git does and check for the file mode, which is 160000 for gitlink trees.
cda1bbd474/cache.h (L96)
This way you can e.g. do network i/o in them.
Thats not a recommended way to do it though, as you work around
a lot of the feature in flatpak-builder like the caching and
verification.
Some projects declare their Git submodules with URLs relative to their
own.
For example, gedit is hosted at git://git.gnome.org/gedit, and has its
libgd submodule declared with the ../libgd URL. We should treat the
latter as git://git.gnome.org/libgd.
This was in fact properly done in the past, but I broke it in commit
1171e1d202.
This fixes it again.
Currently to use a local copy of a git repo you have to specify the url
as "file:///path/to/repo". This commit allows you to specify a path directly
as "/path/to/repo", which is faster and more space-efficient because
git-clone will hardlink the objects rather than copying them.
