Keep the current index contents, and read the contents
- of the named tree-ish under the directory at `<prefix>`. The
- original index file cannot have anything at the path
- `<prefix>` itself, nor anything in the `<prefix>/`
- directory. Note that the `<prefix>/` value must end
+ of the named tree-ish under the directory at `<prefix>`.
+ The command will refuse to overwrite entries that already
+ existed in the original index file. Note that the `<prefix>/`
+ value must end with a slash.
When running the command with `-u` and `-m` options, the
<repository> is the URL of the new submodule's origin repository.
This may be either an absolute URL, or (if it begins with ./
or ../), the location relative to the superproject's origin
-repository. If the superproject doesn't have an origin configured
+repository (Please note that to specify a repository 'foo.git'
+which is located right next to a superproject 'bar.git', you'll
+have to use '../foo.git' instead of './foo.git' - as one might expect
+when following the rules for relative URLs - because the evaluation
+of relative URLs in Git is identical to that of relative directories).
+If the superproject doesn't have an origin configured
the superproject is its own authoritative upstream and the current
working directory is used instead.