This is an enhancement request.

Here

https://git.gnome.org/browse/librsvg/tree/rsvg-styles.c#n778

it is just a matter to add something like:

    } else if (g_str_equal (name, "marker")) {
        state->has_startMarker =
        state->has_middleMarker =
        state->has_endMarker = strcmp (value, "inherit") != 0;
        if (state->has_endMarker) {
            g_free (state->startMarker);
            g_free (state->middleMarker);
            g_free (state->endMarker);
            state->endMarker = rsvg_get_url_string (value);
            state->startMarker = g_strdup (state->endMarker);
            state->middleMarker = g_strdup (state->endMarker);
        }



to get this right the relevant tests in the svg 1.1 test suite are

painting-marker-03-f.svg painting-marker-04-f.svg

Thanks for taking a look at the code!
Would you fancy attaching a patch here? See https://wiki.gnome.org/Git/Developers for more information.

Fixed in commit c8ba1f65fb0df638cffafb9a31b488c2427bb438.