Improve VDP_END handling

- ensure we do send VDP_END down
- try to send it with the last bytes (POLLHUP present
  with a read smaller than the buffer size)

src/tests/error.vtc

@@ -28,6 +28,7 @@ client c1 {
 logexpect l1 -v v1 -g vxid -d 1 -q Error {
 	expect 0 * Begin  {^req \d+ rxreq$}
 	expect * = Error  {^vdfp_pipe: vdp cat: ${cat} stderr: }
+	expect * = Error  {^vdfp_pipe: vdp cat: ${cat} exited with status 1}
 	expect * = End
 } -run
 

src/vdfp_pipe.c

@@ -84,7 +84,7 @@ struct VPFX(pipe_vdp) {
 	struct vdp		*vdp;
 	char			**argv;
 	struct setenv_head	*setenv_head;
-	size_t			bufsz;
+	ssize_t			bufsz;
 	int			argc;
 	int			tmo_ms;
 };
@@ -379,6 +379,7 @@ vdp_bytes(struct vdp_ctx *ctx, enum vdp_action act, void **priv,
 	int retval;
 	ssize_t nbytes;
 	struct VPFX(pipe_vdp) *obj;
+	enum vdp_action act_bytes = VDP_FLUSH;
 
 	CHECK_OBJ_NOTNULL(ctx, VDP_CTX_MAGIC);
 	assert(len >= 0);
@@ -391,14 +392,14 @@ vdp_bytes(struct vdp_ctx *ctx, enum vdp_action act, void **priv,
 	AN(obj->bufsz);
 	fds = state->fds;
 
-	if (act == VDP_END && len == 0)
-		closefd(&fds[STDIN_FILENO].fd);
-
 	for (;;) {
 		fds[STDIN_FILENO].revents = 0;
 		fds[STDOUT_FILENO].revents = 0;
 		fds[STDERR_FILENO].revents = 0;
 
+		if (len == 0 && act == VDP_END && fds[STDIN_FILENO].fd != -1)
+			closefd(&fds[STDIN_FILENO].fd);
+
 		errno = 0;
 		retval = poll(fds, 3, obj->tmo_ms);
 		if (retval < 0) {
@@ -452,14 +453,18 @@ vdp_bytes(struct vdp_ctx *ctx, enum vdp_action act, void **priv,
 			assert(i == STDOUT_FILENO || i == STDERR_FILENO);
 			if (!(fds[i].revents & POLLIN)) {
 				AN(fds[i].revents & POLLHUP);
-				if (i == STDOUT_FILENO)
-					closefd(&fds[STDOUT_FILENO].fd);
-				else
+				if (i == STDERR_FILENO) {
 					closefd(&fds[STDERR_FILENO].fd);
+					continue;
+				}
+				closefd(&fds[STDOUT_FILENO].fd);
+				if (act_bytes != VDP_END)
+					VDP_bytes(ctx, VDP_END, NULL, 0);
 				continue;
 			}
 			errno = 0;
 			nbytes = read(fds[i].fd, state->buf, obj->bufsz);
+
 			if (nbytes < 0) {
 				VSLb(ctx->vsl, SLT_Error, "vdfp_pipe: vdp %s:"
 				     " error reading %s from %s: %s",
@@ -468,15 +473,19 @@ vdp_bytes(struct vdp_ctx *ctx, enum vdp_action act, void **priv,
 				close_all(fds);
 				return (-1);
 			}
+			if (i == STDOUT_FILENO &&
+			    fds[i].revents & POLLHUP &&
+			    nbytes < obj->bufsz) {
+				act_bytes = VDP_END;
+			}
 			if (nbytes == 0) {
 				if (i == STDOUT_FILENO)
 					closefd(&fds[STDOUT_FILENO].fd);
 				else
 					closefd(&fds[STDERR_FILENO].fd);
-				continue;
 			}
 			if (i == STDOUT_FILENO) {
-				retval = VDP_bytes(ctx, VDP_FLUSH, state->buf,
+				retval = VDP_bytes(ctx, act_bytes, state->buf,
 						   nbytes);
 				if (retval < 0) {
 					close_all(fds);
@@ -507,13 +516,9 @@ vdp_bytes(struct vdp_ctx *ctx, enum vdp_action act, void **priv,
 				errmsg += (linelen + 1);
 			}
 		}
-		if (act == VDP_END) {
-			if (fds[STDIN_FILENO].fd != -1 && len == 0)
-				closefd(&fds[STDIN_FILENO].fd);
-			if (fds[STDOUT_FILENO].fd != -1 ||
-			    fds[STDERR_FILENO].fd != -1)
-				continue;
-		}
+		if (act == VDP_END && fds[STDOUT_FILENO].fd != -1)
+			continue;
+
 		if (len == 0)
 			break;
 	}