CLEANUP: muxes/stream-int: Remove flags CS_FL_READ_NULL and SI_FL_READ_NULL

Since the flag CF_SHUTR is no more set to mark the end of the message, these
flags become useless.

This patch should be backported to 1.9.
diff --git a/include/types/connection.h b/include/types/connection.h
index 66a0f46..c7d968c 100644
--- a/include/types/connection.h
+++ b/include/types/connection.h
@@ -87,8 +87,8 @@
 	CS_FL_ERR_PENDING   = 0x00000800,  /* An error is pending, but there's still data to be read */
 	CS_FL_EOS           = 0x00001000,  /* End of stream delivered to data layer */
 	CS_FL_REOS          = 0x00002000,  /* End of stream received (buffer not empty) */
-	CS_FL_READ_NULL     = 0x00004000,  /* Last read received */
-	CS_FL_EOI           = 0x00008000,  /* end-of-input reached */
+	CS_FL_EOI           = 0x00004000,  /* end-of-input reached */
+	/* unused: 0x00008000 */
 	CS_FL_WAIT_FOR_HS   = 0x00010000,  /* This stream is waiting for handhskae */
 	CS_FL_KILL_CONN     = 0x00020000,  /* must kill the connection when the CS closes */
 
diff --git a/include/types/stream_interface.h b/include/types/stream_interface.h
index d1b8135..61937e0 100644
--- a/include/types/stream_interface.h
+++ b/include/types/stream_interface.h
@@ -72,7 +72,7 @@
 	SI_FL_NOLINGER   = 0x00000080,  /* may close without lingering. One-shot. */
 	SI_FL_NOHALF     = 0x00000100,  /* no half close, close both sides at once */
 	SI_FL_SRC_ADDR   = 0x00001000,  /* get the source ip/port with getsockname */
-	SI_FL_READ_NULL  = 0x00000200,   /* Last read reported */
+	/* unused: 0x00000200 */
 	SI_FL_WANT_GET   = 0x00004000,  /* a stream-int would like to get some data from the buffer */
 	SI_FL_CLEAN_ABRT = 0x00008000,  /* SI_FL_ERR is used to report aborts, and not SHUTR */
 
diff --git a/src/mux_h1.c b/src/mux_h1.c
index b191670..65e9915 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -1782,7 +1782,7 @@
 		h1_wake_stream_for_recv(h1s);
 
 	if (conn_xprt_read0_pending(conn) && h1s && h1s->cs)
-		h1s->cs->flags |= (CS_FL_REOS|CS_FL_READ_NULL);
+		h1s->cs->flags |= CS_FL_REOS;
 	if (!b_data(&h1c->ibuf))
 		h1_release_buf(h1c, &h1c->ibuf);
 	else if (!buf_room_for_htx_data(&h1c->ibuf))
@@ -1890,7 +1890,7 @@
 		if (h1c->flags & H1C_F_CS_ERROR || conn->flags & CO_FL_ERROR)
 			flags |= CS_FL_ERROR;
 		if (conn_xprt_read0_pending(conn))
-			flags |= (CS_FL_REOS|CS_FL_READ_NULL);
+			flags |= CS_FL_REOS;
 		h1s->cs->flags |= flags;
 		h1s->cs->data_cb->wake(h1s->cs);
 	}
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 506226c..ab8504e 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -1443,7 +1443,7 @@
 		flags |= CS_FL_ERR_PENDING;
 
 	if (conn_xprt_read0_pending(h2c->conn))
-		flags |= (CS_FL_REOS|CS_FL_READ_NULL);
+		flags |= CS_FL_REOS;
 
 	/* Wake all streams with ID > last */
 	node = eb32_lookup_ge(&h2c->streams_by_id, last + 1);
diff --git a/src/mux_pt.c b/src/mux_pt.c
index 74c802e..4f53920 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -255,7 +255,7 @@
 	if (conn_xprt_read0_pending(cs->conn)) {
 		if (ret == 0)
 			cs->flags &= ~(CS_FL_RCV_MORE | CS_FL_WANT_ROOM);
-		cs->flags |= (CS_FL_EOS|CS_FL_READ_NULL);
+		cs->flags |= CS_FL_EOS;
 	}
 	if (cs->conn->flags & CO_FL_ERROR) {
 		if (ret == 0)
@@ -298,7 +298,7 @@
 
 	ret = cs->conn->xprt->rcv_pipe(cs->conn, pipe, count);
 	if (conn_xprt_read0_pending(cs->conn))
-		cs->flags |= (CS_FL_EOS|CS_FL_READ_NULL);
+		cs->flags |= CS_FL_EOS;
 	if (cs->conn->flags & CO_FL_ERROR)
 		cs->flags |= CS_FL_ERROR;
 	return (ret);
diff --git a/src/stream_interface.c b/src/stream_interface.c
index 1d216ae..d13d695 100644
--- a/src/stream_interface.c
+++ b/src/stream_interface.c
@@ -594,16 +594,6 @@
 		oc->flags |= CF_WRITE_NULL;
 	}
 
-	/* The last read was received but not reported to the channel
-	 * (CS_FL_READ_NULL set but not SI_FL_READ_NULL). So do it, even if the
-	 * EOS was already reported.
-	 *
-	 * NOTE: It is a temporary fix to handle client aborts.
-	 */
-	if (cs->flags & CS_FL_READ_NULL && !(si->flags & SI_FL_READ_NULL)) {
-		si->flags |= SI_FL_READ_NULL;
-		ic->flags |= CF_READ_NULL;
-	}
 	/* Report EOI on the channel if it was reached from the mux point of
 	 * view. */
 	if ((cs->flags & CS_FL_EOI) && !(ic->flags & CF_EOI))