[GSoC][PATCH v5 1/3] submodule: fix buggy $path and $sm_path variable's value

[Prathamesh Chavan <pc44800@gmail.com>]

According to the documentation about git-submodule foreach subcommand's
$path variable:
$path is the name of the submodule directory relative to the superproject

But it was observed when the value of the $path value deviates from this
for the nested submodules when the <command> is run from a subdirectory.
This patch aims for its correction.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
This series of patch is based on gitster/jk/bug-to-abort for untilizing its 
BUG() macro.

The observation made was as follows:
For a project - super containing dir (not a submodule) and a submodule sub 
which contains another submodule subsub. When we run a command from super/dir:

git submodule foreach "echo \$path-\$sm_path"

actual results:
Entering '../sub'
../sub-../sub
Entering '../sub/subsub'
../subsub-../subsub

expected result wrt documentation and current test suite:
Entering '../sub'
sub-../sub
Entering '../sub/subsub'
subsub-../sub/subsub

This make the value of $path confusing and I also feel it deviates from its 
documentation:
$path is the name of the submodule directory relative to the superproject.
Hence, this patch corrects the value assigned to the $path and $sm_path.

 git-submodule.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index c0d0e9a4c..ea6f56337 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -344,9 +344,9 @@ cmd_foreach()
 				prefix="$prefix$sm_path/"
 				sanitize_submodule_env
 				cd "$sm_path" &&
-				sm_path=$(git submodule--helper relative-path "$sm_path" "$wt_prefix") &&
 				# we make $path available to scripts ...
 				path=$sm_path &&
+				sm_path=$displaypath &&
 				if test $# -eq 1
 				then
 					eval "$1"
-- 
2.11.0