submodule deinit: require '--all' instead of '.' for all submodules

The discussion in [1] pointed out that '.' is a faulty suggestion as
there is a corner case where it fails:

> "submodule deinit ." may have "worked" in the sense that you would
> have at least one path in your tree and avoided this "nothing
> matches" most of the time.  It would have still failed with the
> exactly same error if run in an empty repository, i.e.
>
>        $ E=/var/tmp/x/empty && rm -fr "$E" && mkdir -p "$E" && cd "$E"
>        $ git init
>        $ rungit v2.6.6 submodule deinit .
>        error: pathspec '.' did not match any file(s) known to git.
>        Did you forget to 'git add'?
>        $ >file && git add file
>        $ rungit v2.6.6 submodule deinit .
>        $ echo $?
>        0

So instead of a pathspec add the '--all' option to deinit all submodules
and add a test to check for the corner case of an empty repository.

The code only needs to learn about the '--all' option and doesn't
require further changes as `git submodule--helper list "$@"` will list
all submodules when "$@" is empty.

[1] http://news.gmane.org/gmane.comp.version-control.git/289535

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 6 deletions

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 1572f058f5..ad851838cc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -13,7 +13,7 @@ SYNOPSIS
 	      [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]
 'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] init [--] [<path>...]
-'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
+'git submodule' [--quiet] deinit [-f|--force] (--all|[--] <path>...)
 'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch]
 	      [-f|--force] [--rebase|--merge] [--reference <repository>]
 	      [--depth <depth>] [--recursive] [--] [<path>...]
@@ -140,12 +140,15 @@ deinit::
 	tree. Further calls to `git submodule update`, `git submodule foreach`
 	and `git submodule sync` will skip any unregistered submodules until
 	they are initialized again, so use this command if you don't want to
-	have a local checkout of the submodule in your work tree anymore. If
+	have a local checkout of the submodule in your working tree anymore. If
 	you really want to remove a submodule from the repository and commit
 	that use linkgit:git-rm[1] instead.
 +
-If `--force` is specified, the submodule's work tree will be removed even if
-it contains local modifications.
+When the command is run without pathspec, it errors out,
+instead of deinit-ing everything, to prevent mistakes.
++
+If `--force` is specified, the submodule's working tree will
+be removed even if it contains local modifications.
 
 update::
 +
@@ -247,6 +250,10 @@ OPTIONS
 --quiet::
 	Only print error messages.
 
+--all::
+	This option is only valid for the deinit command. Unregister all
+	submodules in the working tree.
+
 -b::
 --branch::
 	Branch of repository to add as submodule.
@@ -257,8 +264,8 @@ OPTIONS
 --force::
 	This option is only valid for add, deinit and update commands.
 	When running add, allow adding an otherwise ignored submodule path.
-	When running deinit the submodule work trees will be removed even if
-	they contain local changes.
+	When running deinit the submodule working trees will be removed even
+	if they contain local changes.
 	When running update (only effective with the checkout procedure),
 	throw away local changes in submodules when switching to a
 	different commit; and always run a checkout operation in the