git submodule foreach: Provide access to submodule name, as '$name'

The argument to 'git submodule foreach' already has access to the variables
'$path' (the path to the submodule, relative to the superproject) and '$sha1'
(the submodule commit recorded by the superproject).

This patch adds another variable -- '$name' -- which contains the name of the
submodule, as recorded in the superproject's .gitmodules file.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-submodule.txt

@@ -131,7 +131,8 @@ summary::
 
 foreach::
 	Evaluates an arbitrary shell command in each checked out submodule.
-	The command has access to the variables $path and $sha1:
+	The command has access to the variables $name, $path and $sha1:
+	$name is the name of the relevant submodule section in .gitmodules,
 	$path is the name of the submodule directory relative to the
 	superproject, and $sha1 is the commit as recorded in the superproject.
 	Any submodules defined in the superproject but not checked out are

git-submodule.sh

@@ -243,6 +243,7 @@ cmd_foreach()
 		if test -e "$path"/.git
 		then
 			say "Entering '$path'"
+			name=$(module_name "$path")
 			(cd "$path" && eval "$@") ||
 			die "Stopping at '$path'; script returned non-zero status."
 		fi