5 files changed, 11 insertions, 2 deletions

diff --git a/compat.c b/compat.c
index bc1131581..8aa43f0f8 100644
--- a/compat.c
+++ b/compat.c
@@ -91,7 +91,8 @@ compat_datafellows(const char *version)
                   "OpenSSH_3.1*",       SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
                 { "OpenSSH_3.*",        SSH_OLD_FORWARD_ADDR },
                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
-                { "OpenSSH*",           0 },
+                { "OpenSSH_4*",         0 },
+                { "OpenSSH*",           SSH_NEW_OPENSSH },
                 { "*MindTerm*",         0 },
                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
                                         SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
diff --git a/compat.h b/compat.h
index 4d8ebc908..5bd89ea73 100644
--- a/compat.h
+++ b/compat.h
@@ -57,6 +57,7 @@
 #define SSH_BUG_FIRSTKEX        0x00800000
 #define SSH_OLD_FORWARD_ADDR    0x01000000
 #define SSH_BUG_RFWD_ADDR       0x02000000
+#define SSH_NEW_OPENSSH         0x04000000
 
 void     enable_compat13(void);
 void     enable_compat20(void);
diff --git a/debian/changelog b/debian/changelog
index 0066dfd58..7b05bd269 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -3,6 +3,10 @@ openssh (1:5.1p1-4) UNRELEASED; urgency=low
   * ssh-copy-id: Strip trailing colons from hostname (closes: #226172,
     LP: #249706; thanks to Karl Goetz for nudging this along; forwarded
     upstream as https://bugzilla.mindrot.org/show_bug.cgi?id=1530).
+  * Backport from upstream CVS (Markus Friedl):
+    - Only send eow and no-more-sessions requests to openssh 5 and newer;
+      fixes interop problems with broken ssh v2 implementations (closes:
+      #495917).
 
  -- Colin Watson <cjwatson@debian.org>  Thu, 09 Oct 2008 12:52:34 +0100
 
diff --git a/nchan.c b/nchan.c
index e0ebf43f1..d31c69b2f 100644
--- a/nchan.c
+++ b/nchan.c
@@ -387,6 +387,8 @@ chan_send_eow2(Channel *c)
                     c->self);
                 return;
         }
+        if (!(datafellows & SSH_NEW_OPENSSH))
+                return;
         packet_start(SSH2_MSG_CHANNEL_REQUEST);
         packet_put_int(c->remote_id);
         packet_put_cstring("eow@openssh.com");
diff --git a/ssh.c b/ssh.c
index e2e2ef498..2b55e6397 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1205,7 +1205,8 @@ ssh_session2(void)
                 id = ssh_session2_open();
 
         /* If we don't expect to open a new session, then disallow it */
-        if (options.control_master == SSHCTL_MASTER_NO) {
+        if (options.control_master == SSHCTL_MASTER_NO &&
+            (datafellows & SSH_NEW_OPENSSH)) {
                 debug("Requesting no-more-sessions@openssh.com");
                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
                 packet_put_cstring("no-more-sessions@openssh.com");