am: return control to caller, for housekeeping

We only need to do these two tasks

    git gc --auto
    rm -fr "$dotest"

ourselves if the script was invoked as a standalone program; when
invoked with --rebasing (from git-rebase--am.sh), cascade control back
to the ultimate caller git-rebase.sh to do this for us.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-am.sh

@@ -906,5 +906,10 @@ if test -s "$dotest"/rewritten; then
     fi
 fi
 
+# If am was called with --rebasing (from git-rebase--am), it's up to
+# the caller to take care of housekeeping.
+if ! test -f "$dotest/rebasing"
+then
 	rm -fr "$dotest"
 	git gc --auto
+fi

git-rebase--am.sh

@@ -7,12 +7,12 @@ case "$action" in
 continue)
 	git am --resolved --resolvemsg="$resolvemsg" &&
 	move_to_original_branch
-	exit
+	return
 	;;
 skip)
 	git am --skip --resolvemsg="$resolvemsg" &&
 	move_to_original_branch
-	exit
+	return
 	;;
 esac
 
@@ -56,7 +56,7 @@ else
 
 		As a result, git cannot rebase them.
 		EOF
-		exit $?
+		return $?
 	fi
 
 	git am $git_am_opt --rebasing --resolvemsg="$resolvemsg" <"$GIT_DIR/rebased-patches"
@@ -68,7 +68,7 @@ fi
 if test 0 != $ret
 then
 	test -d "$state_dir" && write_basic_state
-	exit $ret
+	return $ret
 fi
 
 move_to_original_branch