am doc: add a pointer to relevant hooks

diff --git a/git-rebase.sh b/git-rebase.sh
index 226752fbff62f4f27da95f7d711c898503fd7148..8a3efa2983d08e38d40ae8b6dcecd82b0901ffa1 100755 (executable)
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -14,6 +14,7 @@ git-rebase --continue | --abort | --skip | --edit-todo
 v,verbose!         display a diffstat of what changed upstream
 q,quiet!           be quiet. implies --no-stat
 autostash!         automatically stash/stash pop before and after
+fork-point         use 'merge-base --fork-point' to refine upstream
 onto=!             rebase onto given branch instead of upstream
 p,preserve-merges! try to recreate merges instead of ignoring them
 s,strategy=!       use the given merge strategy
@@ -66,6 +67,7 @@ verbose=
 diffstat=
 test "$(git config --bool rebase.stat)" = true && diffstat=t
 autostash="$(git config --bool rebase.autostash || echo false)"
+fork_point=auto
 git_am_opt=
 rebase_root=
 force_rebase=
@@ -260,6 +262,12 @@ do
        --no-autosquash)
                autosquash=
                ;;
+       --fork-point)
+               fork_point=t
+               ;;
+       --no-fork-point)
+               fork_point=
+               ;;
        -M|-m)
                do_merge=t
                ;;
@@ -437,6 +445,8 @@ then
                        error_on_missing_default_upstream "rebase" "rebase" \
                                "against" "git rebase <branch>"
                fi
+
+               test "$fork_point" = auto && fork_point=t
                ;;
        *)      upstream_name="$1"
                shift
@@ -522,6 +532,16 @@ case "$#" in
        ;;
 esac
 
+if test "$fork_point" = t
+then
+       new_upstream=$(git merge-base --fork-point "$upstream_name" \
+                       "${switch_to:-HEAD}")
+       if test -n "$new_upstream"
+       then
+               upstream=$new_upstream
+       fi
+fi
+
 if test "$autostash" = true && ! (require_clean_work_tree) 2>/dev/null
 then
        stash_sha1=$(git stash create "autostash") ||