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

From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Jul 19, 2008, 17:06 UTC
Message-ID: <1216487215-6927-1-git-send-email-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