At the moment when two items to be saved have the same directory name,
restic only saves the first one to the repo. Let's say we have a
structure like this:
dir1
└── subdir
└── file
dir2
└── subdir
└── file
When restic is run on `dir1/subdir` and `dir2/subdir`, it will only save
the first `subdir`:
$ restic backup dir1/subdir dir2/subdir
[...]
$ restic ls -l latest
drwxr-xr-x 1000 100 0 2017-08-27 20:56:39 /subdir
-rw-r--r-- 1000 100 17 2017-08-27 20:56:39 /subdir/file
That's obviously a bad thing, caused by an early decision to strip the
full path to the files/dirs to save and only leave the last directory.
This commit partly resolves this by handling colliding names and
resolving the conflicts. Restic will now append a counter to the file
(`-123`) until the conflict is resolved. So in the example above, we'll
end up with the following structure:
$ restic ls -l latest
drwxr-xr-x 1000 100 0 2017-08-27 20:56:39 /subdir
-rw-r--r-- 1000 100 17 2017-08-27 20:56:39 /subdir/file
drwxr-xr-x 1000 100 0 2017-08-27 20:56:46 /subdir-1
-rw-r--r-- 1000 100 17 2017-08-27 20:56:46 /subdir-1/file
This partly addresses #549 and closes #1179.
At first I thought that the obvious correction would be to archive the
full path. But it turns out that collisions may still occur: Suppose you
have a file named `foo` in the current directory, and the parent directory
also contains a file `foo`. Archiving these with restic also causes a
collision, since restic strips the `../` from the first file:
$ restic backup ../foo foo
This also happens with `tar`, which does not handle the collision and
will happily archive two files called `foo`.
So, the best way forward is to handle name collisions and archive the
whole path. The latter will be tackled in a separate PR.
