fetch-pack: close output channel after sideband demultiplexer terminates

fetch-pack runs the sideband demultiplexer using start_async(). This facility requires that the asynchronously executed function closes the output file descriptor (see Documentation/technical/api-run-command.txt). But the sideband demultiplexer did not do that. This fixes it. In certain error situations this could lock up a fetch operation on Windows because the asynchronous function is run in a thread; by not closing the output fd the reading end never got EOF and waited for more data indefinitely. On Unix this is not a problem because the asynchronous function is run in a separate process, which exits after the function ends and so implicitly closes the output. Since the pack that is sent over the wire encodes the number of objects in the stream, during normal operation the reading end knows when the stream ends and terminates by itself, and does not lock up. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Sixt committed Jun 8, 2009 at 10:51 UTC 3ef67cf250b14b9c62b2bd21e4d0d5339f5f31e5

1 file changed +3 -1

builtin-fetch-pack.c

+3 -1

@@ -483,7 +483,9 @@ static int sideband_demux(int fd, void *data)

483 {

484 int *xd = data;

485

486 - return recv_sideband("fetch-pack", xd[0], fd);

486 + int ret = recv_sideband("fetch-pack", xd[0], fd);

487 + close(fd);

488 + return ret;

489 }

490

491 static int get_pack(int xd[2], char **pack_lockfile)