[Tarantool-patches] [PATCH] Work-around WSL assert when SO_LINGER is set on unix sockets

["Timur Safin" <tsafin@tarantool.org>]

Using SO_LINGER over unix sockets makes no much sense, though
it's harmless on Linux. The problem is, it breaks majority of 
tests under Windows/WSL with assertion, because setsockopt()
would return EINVAL in that case under WSL.

This is known WSL issue and reported here 
https://github.com/microsoft/WSL/issues/3992

So we filter out SO_LINGER if evio_setsockopt_server is being
called with AF_UNIX family.
 
Branch: https://github.com/tarantool/tarantool/tree/tsafin/gh-4659-wsl-no-linger-assert

 
---
 src/lib/core/evio.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/lib/core/evio.c b/src/lib/core/evio.c
index 2152c15e6..06aa11ce4 100644
--- a/src/lib/core/evio.c
+++ b/src/lib/core/evio.c
@@ -140,13 +140,16 @@ evio_setsockopt_server(int fd, int family, int type)
 		       &on, sizeof(on)))
 		return -1;
 
-	/* Send all buffered messages on socket before take
-	 * control out from close(2) or shutdown(2). */
-	struct linger linger = { 0, 0 };
+	if (family != AF_UNIX) {
+		/* Send all buffered messages on socket before
+		 * take control out from close(2) or shutdown(2). */
+		struct linger linger = { 0, 0 };
+
+		if (sio_setsockopt(fd, SOL_SOCKET, SO_LINGER,
+				&linger, sizeof(linger)))
+			return -1;
+	}
 
-	if (sio_setsockopt(fd, SOL_SOCKET, SO_LINGER,
-		       &linger, sizeof(linger)))
-		return -1;
 	if (type == SOCK_STREAM && family != AF_UNIX &&
 	    evio_setsockopt_keepalive(fd) != 0)
 		return -1;
-- 
2.20.1