patchsubmodule: show_submodule_summary: preserve diff queue

> git-diff with --submodule option stopped printing diff lines after a submodule
> change, because show_submodule_summary reset diff queue.
> ---
>  submodule.c |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/submodule.c b/submodule.c
> index 61cb6e2..5b57536 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -46,6 +46,12 @@ done:
>        return ret;
>  }
>
> +static void diff_q_copy(struct diff_queue_struct *dst,
> +                       struct diff_queue_struct *src)
> +{
> +       memcpy(dst, src, sizeof(struct diff_queue_struct));
> +}
> +
>  void handle_ignore_submodules_arg(struct diff_options *diffopt,
>                                  const char *arg)
>  {
> @@ -71,6 +77,7 @@ void show_submodule_summary(FILE *f, const char *path,
>        struct strbuf sb = STRBUF_INIT;
>        static const char *format = "  %m %s";
>        int fast_forward = 0, fast_backward = 0;
> +       struct diff_queue_struct diff_q_backup;
>
>        if (is_null_sha1(two))
>                message = "(submodule deleted)";
> @@ -83,6 +90,7 @@ void show_submodule_summary(FILE *f, const char *path,
>                message = "(commits not present)";
>
>        if (!message) {
> +               diff_q_copy(&diff_q_backup, &diff_queued_diff);
>                init_revisions(&rev, NULL);
>                setup_revisions(0, NULL, &rev, NULL);
>                rev.left_right = 1;
> @@ -146,6 +154,7 @@ void show_submodule_summary(FILE *f, const char *path,
>                }
>                clear_commit_marks(left, ~0);
>                clear_commit_marks(right, ~0);
> +               diff_q_copy(&diff_queued_diff, &diff_q_backup);
>        }
>        strbuf_release(&sb);
>  }
> --
> 1.7.2.1.22.ge7bdd
>
>