rebase: extract functions out of git_rebase__interactive

The extracted functions are:
  - initiate_action
  - setup_reflog_action
  - init_basic_state
  - init_revisions_and_shortrevisions
  - complete_action

Used by git_rebase__interactive

Signed-off-by: Wink Saville <wink@saville.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase--interactive.sh

@@ -740,8 +740,20 @@ get_missing_commit_check_level () {
 	printf '%s' "$check_level" | tr 'A-Z' 'a-z'
 }
 
-git_rebase__interactive () {
+# Initiate an action. If the cannot be any
-	case "$action" in
+# further action it  may exec a command
+# or exit and not return.
+#
+# TODO: Consider a cleaner return model so it
+# never exits and always return 0 if process
+# is complete.
+#
+# Parameter 1 is the action to initiate.
+#
+# Returns 0 if the action was able to complete
+# and if 1 if further processing is required.
+initiate_action () {
+	case "$1" in
 	continue)
 		if test ! -d "$rewritten"
 		then
@@ -836,8 +848,13 @@ To continue rebase after editing, run:
 	show-current-patch)
 		exec git show REBASE_HEAD --
 		;;
+	*)
+		return 1 # continue
+		;;
 	esac
+}
 
+setup_reflog_action () {
 	comment_for_reflog start
 
 	if test ! -z "$switch_to"
@@ -848,13 +865,102 @@ To continue rebase after editing, run:
 
 		comment_for_reflog start
 	fi
+}
 
+init_basic_state () {
 	orig_head=$(git rev-parse --verify HEAD) || die "$(gettext "No HEAD?")"
 	mkdir -p "$state_dir" || die "$(eval_gettext "Could not create temporary \$state_dir")"
 	rm -f "$(git rev-parse --git-path REBASE_HEAD)"
 
 	: > "$state_dir"/interactive || die "$(gettext "Could not mark as interactive")"
 	write_basic_state
+}
+
+init_revisions_and_shortrevisions () {
+	shorthead=$(git rev-parse --short $orig_head)
+	shortonto=$(git rev-parse --short $onto)
+	if test -z "$rebase_root"
+		# this is now equivalent to ! -z "$upstream"
+	then
+		shortupstream=$(git rev-parse --short $upstream)
+		revisions=$upstream...$orig_head
+		shortrevisions=$shortupstream..$shorthead
+	else
+		revisions=$onto...$orig_head
+		shortrevisions=$shorthead
+	fi
+}
+
+complete_action() {
+	test -s "$todo" || echo noop >> "$todo"
+	test -z "$autosquash" || git rebase--helper --rearrange-squash || exit
+	test -n "$cmd" && git rebase--helper --add-exec-commands "$cmd"
+
+	todocount=$(git stripspace --strip-comments <"$todo" | wc -l)
+	todocount=${todocount##* }
+
+cat >>"$todo" <<EOF
+
+$comment_char $(eval_ngettext \
+	"Rebase \$shortrevisions onto \$shortonto (\$todocount command)" \
+	"Rebase \$shortrevisions onto \$shortonto (\$todocount commands)" \
+	"$todocount")
+EOF
+	append_todo_help
+	gettext "
+	However, if you remove everything, the rebase will be aborted.
+
+	" | git stripspace --comment-lines >>"$todo"
+
+	if test -z "$keep_empty"
+	then
+		printf '%s\n' "$comment_char $(gettext "Note that empty commits are commented out")" >>"$todo"
+	fi
+
+
+	has_action "$todo" ||
+		return 2
+
+	cp "$todo" "$todo".backup
+	collapse_todo_ids
+	git_sequence_editor "$todo" ||
+		die_abort "$(gettext "Could not execute editor")"
+
+	has_action "$todo" ||
+		return 2
+
+	git rebase--helper --check-todo-list || {
+		ret=$?
+		checkout_onto
+		exit $ret
+	}
+
+	expand_todo_ids
+
+	test -d "$rewritten" || test -n "$force_rebase" ||
+	onto="$(git rebase--helper --skip-unnecessary-picks)" ||
+	die "Could not skip unnecessary pick commands"
+
+	checkout_onto
+	if test -z "$rebase_root" && test ! -d "$rewritten"
+	then
+		require_clean_work_tree "rebase"
+		exec git rebase--helper ${force_rebase:+--no-ff} $allow_empty_message \
+			--continue
+	fi
+	do_rest
+}
+
+git_rebase__interactive () {
+	initiate_action "$action"
+	ret=$?
+	if test $ret = 0; then
+		return 0
+	fi
+
+	setup_reflog_action
+	init_basic_state
+
 	if test t = "$preserve_merges"
 	then
 		if test -z "$rebase_root"
@@ -878,18 +984,8 @@ To continue rebase after editing, run:
 		merges_option="--no-merges --cherry-pick"
 	fi
 
-	shorthead=$(git rev-parse --short $orig_head)
+	init_revisions_and_shortrevisions
-	shortonto=$(git rev-parse --short $onto)
+
-	if test -z "$rebase_root"
-		# this is now equivalent to ! -z "$upstream"
-	then
-		shortupstream=$(git rev-parse --short $upstream)
-		revisions=$upstream...$orig_head
-		shortrevisions=$shortupstream..$shorthead
-	else
-		revisions=$onto...$orig_head
-		shortrevisions=$shorthead
-	fi
 	if test t != "$preserve_merges"
 	then
 		git rebase--helper --make-script ${keep_empty:+--keep-empty} \
@@ -960,61 +1056,5 @@ To continue rebase after editing, run:
 		done
 	fi
 
-	test -s "$todo" || echo noop >> "$todo"
+	complete_action
-	test -z "$autosquash" || git rebase--helper --rearrange-squash || exit
-	test -n "$cmd" && git rebase--helper --add-exec-commands "$cmd"
-
-	todocount=$(git stripspace --strip-comments <"$todo" | wc -l)
-	todocount=${todocount##* }
-
-cat >>"$todo" <<EOF
-
-$comment_char $(eval_ngettext \
-	"Rebase \$shortrevisions onto \$shortonto (\$todocount command)" \
-	"Rebase \$shortrevisions onto \$shortonto (\$todocount commands)" \
-	"$todocount")
-EOF
-	append_todo_help
-	gettext "
-	However, if you remove everything, the rebase will be aborted.
-
-	" | git stripspace --comment-lines >>"$todo"
-
-	if test -z "$keep_empty"
-	then
-		printf '%s\n' "$comment_char $(gettext "Note that empty commits are commented out")" >>"$todo"
-	fi
-
-
-	has_action "$todo" ||
-		return 2
-
-	cp "$todo" "$todo".backup
-	collapse_todo_ids
-	git_sequence_editor "$todo" ||
-		die_abort "$(gettext "Could not execute editor")"
-
-	has_action "$todo" ||
-		return 2
-
-	git rebase--helper --check-todo-list || {
-		ret=$?
-		checkout_onto
-		exit $ret
-	}
-
-	expand_todo_ids
-
-	test -d "$rewritten" || test -n "$force_rebase" ||
-	onto="$(git rebase--helper --skip-unnecessary-picks)" ||
-	die "Could not skip unnecessary pick commands"
-
-	checkout_onto
-	if test -z "$rebase_root" && test ! -d "$rewritten"
-	then
-		require_clean_work_tree "rebase"
-		exec git rebase--helper ${force_rebase:+--no-ff} $allow_empty_message \
-			--continue
-	fi
-	do_rest
 }