| Message ID | 20170516160549.53653-1-robertmeyers@google.com |
|---|---|
| State | New |
| Headers | show |
On Tue, May 16, 2017 at 09:05:49AM -0700, Rob Meyers wrote: > We noticed when reading data from a named pipe the first 10 bytes > would get dropped. I traced this to the affected code in > fill_buffer(). The assignment of "dst" was always set to the beginning > of the buffer, and if it hadn't been consumed yet the data would be > overwritten. We could reproduce this by setting up a server that > writes to the named pipe in two small (6 byte) messages with a 1 > second gap between. Without the gap, or if the data is sent as one > message, there's no problem. It's in the accumulation of data between > messages to fulfill a read that this bug is triggered. > > --- > libavformat/aviobuf.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) as just explained in the previous thread, this is not the correct change to fix the issue (just saying so this isnt applied by mistake) [...]
diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c index 0a7c39eacd..4e04cb79e0 100644 --- a/libavformat/aviobuf.c +++ b/libavformat/aviobuf.c @@ -519,9 +519,7 @@ void avio_write_marker(AVIOContext *s, int64_t time, enum AVIODataMarkerType typ static void fill_buffer(AVIOContext *s) { - int max_buffer_size = s->max_packet_size ? - s->max_packet_size : IO_BUFFER_SIZE; - uint8_t *dst = s->buf_end - s->buffer + max_buffer_size < s->buffer_size ? + uint8_t *dst = !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_end : s->buffer; int len = s->buffer_size - (dst - s->buffer);