[PATCH] submodules: don't stumble over symbolic links when cloning recursively

[Jens Lehmann <Jens.Lehmann@web.de>]

Since 69c305178 (submodules: refactor computation of relative gitdir path)
cloning a submodule recursively fails for recursive submodules when a
symbolic link is part of the path to the work tree of the superproject.

This happens when module_clone() tries to find the relative paths between
work tree and git dir. When a symbolic link in current $PWD points to a
directory in a different level determining the number of "../" needed to
traverse to the superprojects work tree leads to a wrong result.

As there is no portable way to say "pwd -P" use cd_to_toplevel to remove
the link from the pwd, which fixes this problem.

A test for this problem has been added to t7406.

Reported-by: Bob Halley <halley@play-bow.org>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
---

Thanks to Bob for providing a very detailed bug report and test case!

 git-submodule.sh            |  4 ++--
 t/t7406-submodule-update.sh | 13 +++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 5629d87..f73e32e 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -186,8 +186,8 @@ module_clone()
 		die "$(eval_gettext "Clone of '\$url' into submodule path '\$sm_path' failed")"
 	fi

-	a=$(cd "$gitdir" && pwd)/
-	b=$(cd "$sm_path" && pwd)/
+	a=$(cd_to_toplevel && cd "$gitdir" && pwd)/
+	b=$(cd_to_toplevel && cd "$sm_path" && pwd)/
 	# normalize Windows-style absolute paths to POSIX-style absolute paths
 	case $a in [a-zA-Z]:/*) a=/${a%%:*}${a#*:} ;; esac
 	case $b in [a-zA-Z]:/*) b=/${b%%:*}${b#*:} ;; esac
diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index dcb195b..05521de 100755
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -636,4 +636,17 @@ test_expect_success 'submodule update properly revives a moved submodule' '
 	)
 '

+test_expect_success 'submodule update can handle symbolic links in pwd' '
+	mkdir -p linked/dir &&
+	ln -s linked/dir linkto &&
+	(
+		cd linkto &&
+		git clone "$TRASH_DIRECTORY"/super_update_r2 super &&
+		(
+			cd super &&
+			git submodule update --init --recursive
+		)
+	)
+'
+
 test_done
-- 
1.7.11.1.166.gb8ff004