Merge branch 'rt/rebase-p-no-merge-summary'

"git rebase -p" internally used the merge machinery, but when
rebasing, there should not be a need for merge summary.

* rt/rebase-p-no-merge-summary:
rebase --preserve-merges: ignore "merge.log" config

diff --combined git-rebase--interactive.sh
index 9dfeb539536c55ba3958032d19c539be9ff4750f,4743c5963a20a2bddedc3768cdb3ba91e58918b9..b8245cd3fa4bfb0bf27fd3092d3b5479b9d4086f
--- 1/git-rebase--interactive.sh
--- 2/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@@ -352,8 -352,9 +352,9 @@@ pick_one_preserving_merges () 
                        msg_content="$(commit_message $sha1)"
                        # No point in merging the first parent, that's HEAD
                        new_parents=${new_parents# $first_parent}
+                       merge_args="--no-log --no-ff"
                        if ! do_with_author output eval \
-                       'git merge --no-ff $strategy_args -m "$msg_content" $new_parents'
+                       'git merge $merge_args $strategy_args -m "$msg_content" $new_parents'
                        then
                                printf "%s\n" "$msg_content" > "$GIT_DIR"/MERGE_MSG
                                die_with_patch $sha1 "Error redoing merge $sha1"
@@@ -671,7 -672,7 +672,7 @@@ skip_unnecessary_picks () 
                                ;;
                        esac
                        ;;
 -              3,#*|3,)
 +              3,"$comment_char"*|3,)
                        # copy comments
                        ;;
                *)