filter-branch: eliminate duplicate mapped parents

diff --git a/git-submodule.sh b/git-submodule.sh
index 6135cfa9127c1da094df59236f926c01721ae58b..b55d83ac46a96ba15fb7ac8cb43b8c279b40d119 100755 (executable)
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -246,9 +246,6 @@ module_name()
 # $3 = URL to clone
 # $4 = reference repository to reuse (empty for independent)
 # $5 = depth argument for shallow clones (empty for deep)
-# $6 = (remote-tracking) starting point for the local branch (empty for HEAD)
-# $7 = local branch to create (empty for a detached HEAD, unless $6 is
-#      also empty, in which case the local branch is left unchanged)
 #
 # Prior to calling, cmd_update checks that a possibly existing
 # path is not a git repository.
@@ -262,8 +259,6 @@ module_clone()
        url=$3
        reference="$4"
        depth="$5"
-       start_point="$6"
-       local_branch="$7"
        quiet=
        if test -n "$GIT_QUIET"
        then
@@ -317,16 +312,7 @@ module_clone()
        echo "gitdir: $rel/$a" >"$sm_path/.git"
 
        rel=$(echo $a | sed -e 's|[^/][^/]*|..|g')
-       (
-               clear_local_git_env
-               cd "$sm_path" &&
-               GIT_WORK_TREE=. git config core.worktree "$rel/$b" &&
-               # ash fails to wordsplit ${local_branch:+-B "$local_branch"...}
-               case "$local_branch" in
-               '') git checkout -f -q ${start_point:+"$start_point"} ;;
-               ?*) git checkout -f -q -B "$local_branch" ${start_point:+"$start_point"} ;;
-               esac
-       ) || die "$(eval_gettext "Unable to setup cloned submodule '\$sm_path'")"
+       (clear_local_git_env; cd "$sm_path" && GIT_WORK_TREE=. git config core.worktree "$rel/$b")
 }
 
 isnumber()
@@ -489,15 +475,16 @@ Use -f if you really want to add it." >&2
                                echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
                        fi
                fi
-               if test -n "$branch"
-               then
-                       start_point="origin/$branch"
-                       local_branch="$branch"
-               else
-                       start_point=""
-                       local_branch=""
-               fi
-               module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" "$depth" "$start_point" "$local_branch" || exit
+               module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" "$depth" || exit
+               (
+                       clear_local_git_env
+                       cd "$sm_path" &&
+                       # ash fails to wordsplit ${branch:+-b "$branch"...}
+                       case "$branch" in
+                       '') git checkout -f -q ;;
+                       ?*) git checkout -f -q -B "$branch" "origin/$branch" ;;
+                       esac
+               ) || die "$(eval_gettext "Unable to checkout submodule '\$sm_path'")"
        fi
        git config submodule."$sm_name".url "$realrepo"
 
@@ -818,9 +805,7 @@ cmd_update()
                fi
                name=$(module_name "$sm_path") || exit
                url=$(git config submodule."$name".url)
-               config_branch=$(get_submodule_config "$name" branch)
-               branch="${config_branch:-master}"
-               local_branch="$branch"
+               branch=$(get_submodule_config "$name" branch master)
                if ! test -z "$update"
                then
                        update_module=$update
@@ -834,19 +819,11 @@ cmd_update()
 
                displaypath=$(relative_path "$prefix$sm_path")
 
-               case "$update_module" in
-               none)
+               if test "$update_module" = "none"
+               then
                        echo "Skipping submodule '$displaypath'"
                        continue
-                       ;;
-               checkout)
-                       local_branch=""
-                       ;;
-               rebase | merge | !*)
-                       ;;
-               *)
-                       die "$(eval_gettext "Invalid update mode '$update_module' for submodule '$name'")"
-               esac
+               fi
 
                if test -z "$url"
                then
@@ -860,8 +837,7 @@ Maybe you want to use 'update --init'?")"
 
                if ! test -d "$sm_path"/.git -o -f "$sm_path"/.git
                then
-                       start_point="origin/${branch}"
-                       module_clone "$sm_path" "$name" "$url" "$reference" "$depth" "$start_point" "$local_branch" || exit
+                       module_clone "$sm_path" "$name" "$url" "$reference" "$depth" || exit
                        cloned_modules="$cloned_modules;$name"
                        subsha1=
                else
@@ -907,7 +883,7 @@ Maybe you want to use 'update --init'?")"
                        case ";$cloned_modules;" in
                        *";$name;"*)
                                # then there is no local change to integrate
-                               update_module='!git reset --hard -q'
+                               update_module=checkout ;;
                        esac
 
                        must_die_on_failure=