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, 1 insertions, 3 deletions

diff --git a/stmhal/input.c b/stmhal/input.c
index b735ca2492..b1c8c1f78f 100644
--- a/stmhal/input.c
+++ b/stmhal/input.c
@@ -39,9 +39,7 @@ STATIC mp_obj_t mp_builtin_input(uint n_args, const mp_obj_t *args) {
     if (line.len == 0 && ret == CHAR_CTRL_D) {
         nlr_raise(mp_obj_new_exception(&mp_type_EOFError));
     }
-    mp_obj_t o = mp_obj_new_str(line.buf, line.len, false);
-    vstr_clear(&line);
-    return o;
+    return mp_obj_new_str_from_vstr(&mp_type_str, &line);
 }
 
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin_input_obj, 0, 1, mp_builtin_input);