py: Change vstr so that it doesn't null terminate buffer by default.

This cleans up vstr so that it's a pure "variable buffer", and the user
can decide whether they need to add a terminating null byte.  In most
places where vstr is used, the vstr did not need to be null terminated
and so this patch saves code size, a tiny bit of RAM, and makes vstr
usage more efficient.  When null termination is needed it must be
done explicitly using vstr_null_terminate.

1 files changed, 0 insertions, 2 deletions

diff --git a/stmhal/modusocket.c b/stmhal/modusocket.c
index b52a9c8e88..a2ec08f59e 100644
--- a/stmhal/modusocket.c
+++ b/stmhal/modusocket.c
@@ -217,7 +217,6 @@ STATIC mp_obj_t socket_recv(mp_obj_t self_in, mp_obj_t len_in) {
         return mp_const_empty_bytes;
     }
     vstr.len = ret;
-    vstr.buf[vstr.len] = '\0';
     return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(socket_recv_obj, socket_recv);
@@ -269,7 +268,6 @@ STATIC mp_obj_t socket_recvfrom(mp_obj_t self_in, mp_obj_t len_in) {
         tuple[0] = mp_const_empty_bytes;
     } else {
         vstr.len = ret;
-        vstr.buf[vstr.len] = '\0';
         tuple[0] = mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
     }
     tuple[1] = mod_network_format_inet_addr(ip, port);