[PATCH] Ensure that SSH runs in non-interactive mode

[Fredrik Tolf <fredrik@dolda2000.com>]

OpenSSH has the nice feature that it sets the IP TOS value of its
connection depending on usage. When used in interactive mode, it
is set to Minimize-Delay, and other wise to Maximize-Throughput. Its
usage by Git is best served by Maximize-Throughput, for obvious
reasons.

However, it seems to use a DWIM heuristic for detecting interactive
mode. The current implementation enters interactive mode if either
a PTY is allocated or X11 forwarding is enabled, and even though Git
SSH:ing does not allocate a PTY, X11 forwarding is often turned on
by default. By removing the DISPLAY env variable before forking, SSH
can thus be forced into non-interactive mode, without any obvious
ill effects.

Signed-off-by: Fredrik Tolf <fredrik@dolda2000.com>
---
 connect.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/connect.c b/connect.c
index 574f42f..54888d3 100644
--- a/connect.c
+++ b/connect.c
@@ -607,6 +607,13 @@ struct child_process *git_connect(int fd[2], const char *url_orig,
 			*arg++ = port;
 		}
 		*arg++ = host;
+		/* Remove the X11 DISPLAY from the environment, to
+		 * make SSH run non-interactively */
+		const char *env[] = {
+			"DISPLAY",
+			NULL
+		};
+		conn->env = env;
 	}
 	else {
 		/* remove these from the environment */
-- 
1.5.6.2