Merge branch 'ph/submodule-rebase'

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

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

diff --combined Documentation/git-submodule.txt
index cd8e861ce4ae33b25928a16aa213933d2a38a155,2289d11f0e350886296bf961a9acb2e9b6f0ffd9..470bd75ad9ca7760bef33c1c4a326c79da92eb2b
--- 1/Documentation/git-submodule.txt
--- 2/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@@ -9,12 -9,10 +9,12 @@@ git-submodule - Initialize, update or i
  SYNOPSIS
  --------
  [verse]
 -'git submodule' [--quiet] add [-b branch] [--] <repository> <path>
 +'git submodule' [--quiet] add [-b branch]
 +            [--reference <repository>] [--] <repository> <path>
  'git submodule' [--quiet] status [--cached] [--] [<path>...]
  'git submodule' [--quiet] init [--] [<path>...]
 -'git submodule' [--quiet] update [--init] [-N|--no-fetch] [--rebase] [--] [<path>...]
 +'git submodule' [--quiet] update [--init] [-N|--no-fetch] [--rebase]
 +            [--reference <repository>] [--] [<path>...]
  'git submodule' [--quiet] summary [--summary-limit <n>] [commit] [--] [<path>...]
  'git submodule' [--quiet] foreach <command>
  'git submodule' [--quiet] sync [--] [<path>...]
@@@ -115,8 -113,9 +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
@@@ -180,23 -179,25 +181,33 @@@ OPTION
        This option is only valid for the update command.
        Don't fetch new objects from the remote site.
  
 ---rebase::
 -      This option is only valid for the update command.
 -      Rebase the current branch onto the commit recorded in the
 -      superproject. If this option is given, the submodule's HEAD will not
 -      be detached. If a a merge failure prevents this process, you will have
 -      to resolve these failures with linkgit:git-rebase[1].
 -      If the key `submodule.$name.update` is set to `rebase`, this option is
 -      implicit.
 -
+ --merge::
+       This option is only valid for the update command.
+       Merge the commit recorded in the superproject into the current branch
+       of the submodule. If this option is given, the submodule's HEAD will
+       not be detached. If a merge failure prevents this process, you will
+       have to resolve the resulting conflicts within the submodule with the
+       usual conflict resolution tools.
+       If the key `submodule.$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
 +      superproject. If this option is given, the submodule's HEAD will not
 +      be detached. If a a merge failure prevents this process, you will have
 +      to resolve these failures with linkgit:git-rebase[1].
 +      If the key `submodule.$name.update` is set to `rebase`, this option is
 +      implicit.
 +
 +--reference <repository>::
 +      This option is only valid for add and update commands.  These
 +      commands sometimes need to clone a remote repository. In this case,
 +      this option will be passed to the linkgit:git-clone[1] command.
 ++
 +*NOTE*: Do *not* use this option unless you have read the note
 +for linkgit:git-clone[1]'s --reference and --shared options carefully.
 +
  <path>...::
        Paths to submodule(s). When specified this will restrict the command
        to only operate on the submodules found at the specified paths.

diff --combined git-submodule.sh
index 19a3a840fdc7eed4994741e13306b71a3ffd2ada,3aff37970ad22c2498e1b2755a214e2fdb183f21..f4f35626713bd8ec238262731b0fd2ab59d6f07f
--- 1/git-submodule.sh
--- 2/git-submodule.sh
+++ b/git-submodule.sh
@@@ -5,7 -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
@@@ -15,7 -15,6 +15,7 @@@ require_work_tre
  command=
  branch=
  quiet=
 +reference=
  cached=
  nofetch=
  update=
@@@ -93,7 -92,6 +93,7 @@@ module_clone(
  {
        path=$1
        url=$2
 +      reference="$3"
  
        # If there already is a directory at the submodule path,
        # expect it to be empty (since that is the default checkout
@@@ -109,12 -107,7 +109,12 @@@
        test -e "$path" &&
        die "A file already exist at path '$path'"
  
 -      git-clone -n "$url" "$path" ||
 +      if test -n "$reference"
 +      then
 +              git-clone "$reference" -n "$url" "$path"
 +      else
 +              git-clone -n "$url" "$path"
 +      fi ||
        die "Clone of '$url' into submodule path '$path' failed"
  }
  
@@@ -139,15 -132,6 +139,15 @@@ cmd_add(
                -q|--quiet)
                        quiet=1
                        ;;
 +              --reference)
 +                      case "$2" in '') usage ;; esac
 +                      reference="--reference=$2"
 +                      shift
 +                      ;;
 +              --reference=*)
 +                      reference="$1"
 +                      shift
 +                      ;;
                --)
                        shift
                        break
@@@ -220,7 -204,7 +220,7 @@@
                git config submodule."$path".url "$url"
        else
  
 -              module_clone "$path" "$realrepo" || exit
 +              module_clone "$path" "$realrepo" "$reference" || exit
                (
                        unset GIT_DIR
                        cd "$path" &&
@@@ -336,8 -320,8 +336,8 @@@ cmd_update(
                        quiet=1
                        ;;
                -i|--init)
 +                      init=1
                        shift
 -                      cmd_init "$@" || return
                        ;;
                -N|--no-fetch)
                        shift
@@@ -347,15 -331,10 +347,19 @@@
                        shift
                        update="rebase"
                        ;;
 +              --reference)
 +                      case "$2" in '') usage ;; esac
 +                      reference="--reference=$2"
 +                      shift 2
 +                      ;;
 +              --reference=*)
 +                      reference="$1"
 +                      shift
 +                      ;;
+               -m|--merge)
+                       shift
+                       update="merge"
+                       ;;
                --)
                        shift
                        break
@@@ -369,11 -348,6 +373,11 @@@
                esac
        done
  
 +      if test -n "$init"
 +      then
 +              cmd_init "--" "$@" || return
 +      fi
 +
        module_list "$@" |
        while read mode sha1 stage path
        do
@@@ -392,7 -366,7 +396,7 @@@
  
                if ! test -d "$path"/.git -o -f "$path"/.git
                then
 -                      module_clone "$path" "$url" || exit
 +                      module_clone "$path" "$url" "$reference"|| exit
                        subsha1=
                else
                        subsha1=$(unset GIT_DIR; cd "$path" &&
@@@ -426,6 -400,11 +430,11 @@@
                                action="rebase"
                                msg="rebased onto"
                                ;;
+                       merge)
+                               command="git merge"
+                               action="merge"
+                               msg="merged in"
+                               ;;
                        *)
                                command="git checkout $force -q"
                                action="checkout"