[PATCH v2 2/2] submodule: fix handling of superproject with relative origin URLs

[Jon Seymour <jon.seymour@gmail.com>]

Prior to this change, an operation such as git submodule add, init or
sync produced the wrong result when the origin URL of the superproject
was itself a relative URL.

The issue arises in these cases because the origin URL of
the superproject needs to be prepended with a prefix that navigates
from the submodule to the superproject so that when the submodule
URL is concatenated the resulting URL is relative to the working tree
of the submodule.

This change ensures that this is done for add, sync and init.

Note that superproject relative origin URLs of the form foo/bar
are still not handled correctly. The user can workaround this case
by adding ./ prefix to the origin URL.

Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
---
 git-submodule.sh           | 35 ++++++++++++++++++++---------------
 t/t7400-submodule-basic.sh |  4 ++--
 t/t7403-submodule-sync.sh  |  2 +-
 3 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 64a70d6..230c219 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -45,6 +45,10 @@ resolve_relative_url ()
 		../*)
 			url="${url#../}"
 			case "$remoteurl" in
+			.*/*)
+				up_path="$(echo "$2" | sed "s/[^/]*/../g")"
+				remoteurl="${up_path%/}/${remoteurl%/*}"
+				;;
 			*/*)
 				remoteurl="${remoteurl%/*}"
 				;;
@@ -235,11 +239,24 @@ cmd_add()
 		usage
 	fi
 
+	# normalize path:
+	# multiple //; leading ./; /./; /../; trailing /
+	sm_path=$(printf '%s/\n' "$sm_path" |
+		sed -e '
+			s|//*|/|g
+			s|^\(\./\)*||
+			s|/\./|/|g
+			:start
+			s|\([^/]*\)/\.\./||
+			tstart
+			s|/*$||
+		')
+
 	# assure repo is absolute or relative to parent
 	case "$repo" in
 	./*|../*)
 		# dereference source url relative to parent's url
-		realrepo=$(resolve_relative_url "$repo") || exit
+		realrepo=$(resolve_relative_url "$repo" "$sm_path") || exit
 		;;
 	*:*|/*)
 		# absolute url
@@ -250,18 +267,6 @@ cmd_add()
 	;;
 	esac
 
-	# normalize path:
-	# multiple //; leading ./; /./; /../; trailing /
-	sm_path=$(printf '%s/\n' "$sm_path" |
-		sed -e '
-			s|//*|/|g
-			s|^\(\./\)*||
-			s|/\./|/|g
-			:start
-			s|\([^/]*\)/\.\./||
-			tstart
-			s|/*$||
-		')
 	git ls-files --error-unmatch "$sm_path" > /dev/null 2>&1 &&
 	die "$(eval_gettext "'\$sm_path' already exists in the index")"
 
@@ -407,7 +412,7 @@ cmd_init()
 			# Possibly a url relative to parent
 			case "$url" in
 			./*|../*)
-				url=$(resolve_relative_url "$url") || exit
+				url=$(resolve_relative_url "$url" "$sm_path") || exit
 				;;
 			esac
 			git config submodule."$name".url "$url" ||
@@ -964,7 +969,7 @@ cmd_sync()
 		# Possibly a url relative to parent
 		case "$url" in
 		./*|../*)
-			url=$(resolve_relative_url "$url") || exit
+			url=$(resolve_relative_url "$url" "$sm_path") || exit
 			;;
 		esac
 
diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 1c40951..e10abc4 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -507,7 +507,7 @@ test_expect_success 'relative path works with user@host:path' '
 	)
 '
 
-test_expect_failure 'relative path works with ../relative/repo' '
+test_expect_success 'relative path works with ../relative/repo' '
 	(
 		cd reltest &&
 		cp pristine-.git-config .git/config &&
@@ -517,7 +517,7 @@ test_expect_failure 'relative path works with ../relative/repo' '
 	)
 '
 
-test_expect_failure 'test that submodule add creates the correct url when super origin url is relative' '
+test_expect_success 'test that submodule add creates the correct url when super origin url is relative' '
 	mkdir reladd &&
 	(
 		cd reladd &&
diff --git a/t/t7403-submodule-sync.sh b/t/t7403-submodule-sync.sh
index 788bc24..35700ef 100755
--- a/t/t7403-submodule-sync.sh
+++ b/t/t7403-submodule-sync.sh
@@ -86,7 +86,7 @@ test_expect_success '"git submodule sync" should not vivify uninteresting submod
 	)
 '
 
-test_expect_failure '"git submodule sync" should handle a super with a relative origin URL' '
+test_expect_success '"git submodule sync" should handle a super with a relative origin URL' '
 	git clone super relative-clone &&
 	(cd relative-clone &&
 	 git submodule update --init &&
-- 
1.7.10.2.650.g22d2504