Merge branch 'sp/merge' (early part)

* 'sp/merge' (early part):
Improve merge performance by avoiding in-index merges.

diff --combined git-merge.sh
index 7de83dc76c442e2187c66d32bc704a063ab83781,1c4f6693f5b6919da2a867a02465a382477cfcac..7b590268edb44cc5455fe9bdbcbfc0698a6fb800
--- 1/git-merge.sh
--- 2/git-merge.sh
+++ b/git-merge.sh
@@@ -5,14 -5,11 +5,14 @@@
  
  USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commit>+'
  
 +SUBDIRECTORY_OK=Yes
  . git-sh-setup
  set_reflog_action "merge $*"
 +require_work_tree
 +cd_to_toplevel
  
  test -z "$(git ls-files -u)" ||
 -      die "You are in a middle of conflicted merge."
 +      die "You are in the middle of a conflicted merge."
  
  LF='
  '
@@@ -301,24 -298,30 +301,30 @@@ f,*
        ;;
  ?,1,*,)
        # We are not doing octopus, not fast forward, and have only
-       # one common.  See if it is really trivial.
-       git var GIT_COMMITTER_IDENT >/dev/null || exit
- 
-       echo "Trying really trivial in-index merge..."
+       # one common.
        git-update-index --refresh 2>/dev/null
-       if git-read-tree --trivial -m -u -v $common $head "$1" &&
-          result_tree=$(git-write-tree)
-       then
-           echo "Wonderful."
-           result_commit=$(
-               echo "$merge_msg" |
-               git-commit-tree $result_tree -p HEAD -p "$1"
-           ) || exit
-           finish "$result_commit" "In-index merge"
-           dropsave
-           exit 0
-       fi
-       echo "Nope."
+       case " $use_strategies " in
+       *' recursive '*|*' recur '*)
+               : run merge later
+               ;;
+       *)
+               # See if it is really trivial.
+               git var GIT_COMMITTER_IDENT >/dev/null || exit
+               echo "Trying really trivial in-index merge..."
+               if git-read-tree --trivial -m -u -v $common $head "$1" &&
+                  result_tree=$(git-write-tree)
+               then
+                       echo "Wonderful."
+                       result_commit=$(
+                               echo "$merge_msg" |
+                               git-commit-tree $result_tree -p HEAD -p "$1"
+                       ) || exit
+                       finish "$result_commit" "In-index merge"
+                       dropsave
+                       exit 0
+               fi
+               echo "Nope."
+       esac
        ;;
  *)
        # An octopus.  If we can reach all the remote we are up to date.