Merge branch 'ph/submodule-rebase'

* ph/submodule-rebase:
  git-submodule: add support for --merge.

Conflicts:
	Documentation/git-submodule.txt
	git-submodule.sh

4 files changed, 86 insertions, 6 deletions

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index cd8e861ce4..470bd75ad9 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -115,8 +115,9 @@ init::
 update::
 	Update the registered submodules, i.e. clone missing submodules and
 	checkout the commit specified in the index of the containing repository.
-	This will make the submodules HEAD be detached unless '--rebase' is
-	specified or the key `submodule.$name.update` is set to	`rebase`.
+	This will make the submodules HEAD be detached unless '--rebase' or
+	'--merge' is specified or the key `submodule.$name.update` is set to
+	`rebase` or `merge`.
 +
 If the submodule is not yet initialized, and you just want to use the
 setting as stored in .gitmodules, you can automatically initialize the
@@ -180,6 +181,16 @@ OPTIONS
 	This option is only valid for the update command.
 	Don't fetch new objects from the remote site.
 
+--merge::
+	This option is only valid for the update command.
+	Merge the commit recorded in the superproject into the current branch
+	of the submodule. If this option is given, the submodule's HEAD will
+	not be detached. If a merge failure prevents this process, you will
+	have to resolve the resulting conflicts within the submodule with the
+	usual conflict resolution tools.
+	If the key `submodule.$name.update` is set to `merge`, this option is
+	implicit.
+
 --rebase::
 	This option is only valid for the update command.
 	Rebase the current branch onto the commit recorded in the
diff --git a/Documentation/gitmodules.txt b/Documentation/gitmodules.txt
index 1b67f0a9f1..5daf750d19 100644
--- a/Documentation/gitmodules.txt
+++ b/Documentation/gitmodules.txt
@@ -35,9 +35,11 @@ submodule.<name>.update::
 	If 'checkout' (the default), the new commit specified in the
 	superproject will be checked out in the submodule on a detached HEAD.
 	If 'rebase', the current branch of the submodule will be rebased onto
-	the commit specified in the superproject.
+	the commit specified in the superproject. If 'merge', the commit
+	specified in the superproject will be merged into the current branch
+	in the submodule.
 	This config option is overridden if 'git submodule update' is given
-	the '--rebase' option.
+	the '--merge' or '--rebase' options.
 
 
 EXAMPLES
diff --git a/git-submodule.sh b/git-submodule.sh
index 19a3a840fd..f4f3562671 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -5,7 +5,7 @@
 # Copyright (c) 2007 Lars Hjemli
 
 USAGE="[--quiet] [--cached] \
-[add [-b branch] <repo> <path>]|[status|init|update [-i|--init] [-N|--no-fetch]|summary [-n|--summary-limit <n>] [<commit>]] \
+[add [-b branch] <repo> <path>]|[status|init|update [-i|--init] [-N|--no-fetch] [--rebase|--merge]|summary [-n|--summary-limit <n>] [<commit>]] \
 [--] [<path>...]|[foreach <command>]|[sync [--] [<path>...]]"
 OPTIONS_SPEC=
 . git-sh-setup
@@ -356,6 +356,10 @@ cmd_update()
 			reference="$1"
 			shift
 			;;
+		-m|--merge)
+			shift
+			update="merge"
+			;;
 		--)
 			shift
 			break
@@ -426,6 +430,11 @@ cmd_update()
 				action="rebase"
 				msg="rebased onto"
 				;;
+			merge)
+				command="git merge"
+				action="merge"
+				msg="merged in"
+				;;
 			*)
 				command="git checkout $force -q"
 				action="checkout"
diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index 0773fe405b..2d33d9efec 100755
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -6,7 +6,7 @@
 test_description='Test updating submodules
 
 This test verifies that "git submodule update" detaches the HEAD of the
-submodule and "git submodule update --rebase" does not detach the HEAD.
+submodule and "git submodule update --rebase/--merge" does not detach the HEAD.
 '
 
 . ./test-lib.sh
@@ -76,6 +76,20 @@ test_expect_success 'submodule update --rebase staying on master' '
 	)
 '
 
+test_expect_success 'submodule update --merge staying on master' '
+	(cd super/submodule &&
+	  git reset --hard HEAD~1
+	) &&
+	(cd super &&
+	 (cd submodule &&
+	  compare_head
+	 ) &&
+	 git submodule update --merge submodule &&
+	 cd submodule &&
+	 compare_head
+	)
+'
+
 test_expect_success 'submodule update - rebase in .git/config' '
 	(cd super &&
 	 git config submodule.submodule.update rebase
@@ -110,6 +124,40 @@ test_expect_success 'submodule update - checkout in .git/config but --rebase giv
 	)
 '
 
+test_expect_success 'submodule update - merge in .git/config' '
+	(cd super &&
+	 git config submodule.submodule.update merge
+	) &&
+	(cd super/submodule &&
+	  git reset --hard HEAD~1
+	) &&
+	(cd super &&
+	 (cd submodule &&
+	  compare_head
+	 ) &&
+	 git submodule update submodule &&
+	 cd submodule &&
+	 compare_head
+	)
+'
+
+test_expect_success 'submodule update - checkout in .git/config but --merge given' '
+	(cd super &&
+	 git config submodule.submodule.update checkout
+	) &&
+	(cd super/submodule &&
+	  git reset --hard HEAD~1
+	) &&
+	(cd super &&
+	 (cd submodule &&
+	  compare_head
+	 ) &&
+	 git submodule update --merge submodule &&
+	 cd submodule &&
+	 compare_head
+	)
+'
+
 test_expect_success 'submodule update - checkout in .git/config' '
 	(cd super &&
 	 git config submodule.submodule.update checkout
@@ -137,4 +185,14 @@ test_expect_success 'submodule init picks up rebase' '
 	)
 '
 
+test_expect_success 'submodule init picks up merge' '
+	(cd super &&
+	 git config submodule.merging.url git://non-existing/git &&
+	 git config submodule.merging.path does-not-matter &&
+	 git config submodule.merging.update merge &&
+	 git submodule init merging &&
+	 test "merge" = $(git config submodule.merging.update)
+	)
+'
+
 test_done