\iow_close:N does nothing for \g_tmpa_iow

[Witiko]

\iow_close:N is defined as follows:

latex3/l3kernel/l3file.dtx

Lines 1553 to 1563 in d210490

	\cs_new_protected:Npn \iow_close:N #1
	{
	\int_compare:nT { - \c_log_iow < #1 < \c_term_iow }
	{
	\tex_immediate:D \tex_closeout:D #1
	\prop_gremove:NV \g_@@_streams_prop #1
	\seq_if_in:NVF \g_@@_streams_seq #1
	{ \seq_gpush:NV \g_@@_streams_seq #1 }
	\cs_gset_eq:NN #1 \c_term_iow
	}
	}

However, \g_tmpa_iow does not seem to satisfy {- \c_log_iow < #1 < \c_term_iow }. Processing the following source with up-to-date pdfTeX produces a PDF document with the text false:

\input expl3-generic\relax
\ExplSyntaxOn
\iow_open:Nn
  \g_tmpa_iow
  { foo.bar }
\iow_now:Nn
  \g_tmpa_iow
  { baz }
\int_compare:nTF
  { - \c_log_iow < \g_tmpa_iow < \c_term_iow }
  { true  }
  { false }
\iow_close:N
  \g_tmpa_iow
\ExplSyntaxOff
\bye

This seems to suggest that the final \iow_close:N \g_tmpa_iow will do nothing, which does not seem right.

This has practical repercussions. Without a \closeout, I have no guarantee that my write has been flushed. Indeed, if I place ~\input_file:n { foo.bar } below \iow_close:N \g_tmpa_iow, processing the source with pdfTeX will still only produce the text false. It is only after replacing \iow_close:N with \immediate \closeout that processing the source with pdfTeX produces the text false baz as would be expected.