commit 6077141f4affdab9b7ce97a9b1c6859825eaaa29 Author: David Fifield david@bamsoftware.com Date: Sun Jun 10 16:41:32 2018 -0700

Log to io.Discard if no log file is set.

https://bugs.torproject.org/25600#comment:14

Snowflake in Tor Browser has been hanging after surfing for a while. (Tor reports "no running bridges".) It only began happening after commit 12922a232b, which caused snowflake-client not to log to a file by default (leaving it to log to its default stderr). What seems to be happening is that tor doesn't read from its PT clients' stderr, leaving a buffer to fill up that eventually causes a hang. --- client/snowflake.go | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/client/snowflake.go b/client/snowflake.go index e0f9746..a9841be 100644 --- a/client/snowflake.go +++ b/client/snowflake.go @@ -150,6 +150,8 @@ func main() { } defer logFile.Close() log.SetOutput(logFile) + } else { + log.SetOutput(ioutil.Discard) }

log.Println("\n\n\n --- Starting Snowflake Client ---")