Index: lib/xtrans/Xtrans.c
===================================================================
RCS file: /cvs/xorg/lib/xtrans/Xtrans.c,v
retrieving revision 1.6
diff -u -r1.6 Xtrans.c
--- lib/xtrans/Xtrans.c	8 Nov 2005 06:33:26 -0000	1.6
+++ lib/xtrans/Xtrans.c	17 Mar 2006 04:08:40 -0000
@@ -1400,3 +1400,6 @@
 #endif /* NEED_UTSNAME */
     return len;
 }
+
+/* vim:set ts=8 sw=4: */
+
Index: lib/xtrans/Xtrans.h
===================================================================
RCS file: /cvs/xorg/lib/xtrans/Xtrans.h,v
retrieving revision 1.2
diff -u -r1.2 Xtrans.h
--- lib/xtrans/Xtrans.h	23 Apr 2004 18:44:27 -0000	1.2
+++ lib/xtrans/Xtrans.h	17 Mar 2006 04:08:40 -0000
@@ -488,3 +488,6 @@
 #endif
 
 #endif /* _XTRANS_H_ */
+
+/* vim:set ts=8 sw=4: */
+
Index: lib/xtrans/Xtransint.h
===================================================================
RCS file: /cvs/xorg/lib/xtrans/Xtransint.h,v
retrieving revision 1.4
diff -u -r1.4 Xtransint.h
--- lib/xtrans/Xtransint.h	8 Nov 2005 06:33:26 -0000	1.4
+++ lib/xtrans/Xtransint.h	17 Mar 2006 04:08:40 -0000
@@ -374,9 +374,15 @@
 #define TRANS_DISABLED	(1<<2)	/* Don't open this one */
 #define TRANS_NOLISTEN  (1<<3)  /* Don't listen on this one */
 #define TRANS_NOUNLINK	(1<<4)	/* Dont unlink transport endpoints */
+#ifdef HAVE_ABSTRACT_SOCKETS
+/* XXX: should be safe enough to define this unconditionally */
+#define TRANS_ABSTRACT	(1<<5)	/* Use abstract sockets if available */
 
 /* Flags to preserve when setting others */
+#define TRANS_KEEPFLAGS	(TRANS_NOUNLINK|TRANS_ABSTRACT)
+#else
 #define TRANS_KEEPFLAGS	(TRANS_NOUNLINK)
+#endif
 
 /*
  * readv() and writev() don't exist or don't work correctly on some
@@ -483,3 +489,6 @@
 #endif /* XTRANSDEBUG */
 
 #endif /* _XTRANSINT_H_ */
+
+/* vim:set ts=8 sw=4: */
+
Index: lib/xtrans/Xtranssock.c
===================================================================
RCS file: /cvs/xorg/lib/xtrans/Xtranssock.c,v
retrieving revision 1.11
diff -u -r1.11 Xtranssock.c
--- lib/xtrans/Xtranssock.c	8 Nov 2005 06:33:26 -0000	1.11
+++ lib/xtrans/Xtranssock.c	17 Mar 2006 04:08:43 -0000
@@ -831,23 +831,41 @@
 
 #ifdef UNIXCONN
 static int
-set_sun_path(const char *port, const char *upath, char *path)
+set_sun_path(const char *port, const char *upath, char *path
+#ifdef HAVE_ABSTRACT_SOCKETS
+	, int abstract
+#endif
+	)
 {
     struct sockaddr_un s;
     int maxlen = sizeof(s.sun_path) - 1;
+#ifdef HAVE_ABSTRACT_SOCKETS
+    const char *at = abstract ? "@" : "";
+#define ABSTRACTPREFIX "%s"
+#define ABSTRACTARG , at
+#else
+#define ABSTRACTPREFIX 
+#define ABSTRACTARG 
+#endif
 
     if (!port || !*port || !path)
 	return -1;
 
-    if (*port == '/') { /* a full pathname */
-	if (strlen(port) > maxlen)
-	    return -1;
-	sprintf(path, "%s", port);
-    } else {
-	if (strlen(port) + strlen(upath) > maxlen)
-	    return -1;
-	sprintf(path, "%s%s", upath, port);
-    }
+#ifdef HAVE_ABSTRACT_SOCKETS
+    at = "";
+    if (port[0] == '@')
+	upath = "";
+    else if (abstract)
+	at = "@";
+#endif
+    if (*port == '/') /* a full pathname */
+	upath = "";
+
+    if (strlen(port) + strlen(upath) > maxlen)
+	return -1;
+    sprintf(path, ABSTRACTPREFIX "%s%s" ABSTRACTARG , upath, port);
+#undef ABSTRACTPREFIX
+#undef ABSTRACTARG
     return 0;
 }
 #endif
@@ -1070,6 +1088,14 @@
     int			oldUmask;
     int			status;
     unsigned int	mode;
+    char		tmpport[64];
+
+#ifdef HAVE_ABSTRACT_SOCKETS
+    int			abstract = ciptr->transptr->flags & TRANS_ABSTRACT;
+#define ABSTRACTARG , abstract
+#else
+#define ABSTRACTARG 
+#endif
 
     PRMSG (2, "SocketUNIXCreateListener(%s)\n",
 	port ? port : "NULL", 0, 0);
@@ -1094,13 +1120,13 @@
 
     sockname.sun_family = AF_UNIX;
 
-    if (port && *port) {
-	if (set_sun_path(port, UNIX_PATH, sockname.sun_path) != 0) {
-	    PRMSG (1, "SocketUNIXCreateListener: path too long\n", 0, 0, 0);
-	    return TRANS_CREATE_LISTENER_FAILED;
-	}
-    } else {
-	sprintf (sockname.sun_path, "%s%ld", UNIX_PATH, (long)getpid());
+    if (! (port && *port)) {
+	sprintf (tmpport, "%ld", (long)getpid());
+	port = tmpport;
+    }
+    if (set_sun_path(port, UNIX_PATH, sockname.sun_path ABSTRACTARG) != 0) {
+	PRMSG (1, "SocketUNIXCreateListener: path too long\n", 0, 0, 0);
+	return TRANS_CREATE_LISTENER_FAILED;
     }
 
 #if (defined(BSD44SOCKETS) || defined(__UNIXWARE__)) && !defined(Lynx)
@@ -1110,7 +1136,12 @@
     namelen = strlen(sockname.sun_path) + sizeof(sockname.sun_family);
 #endif
 
-    unlink (sockname.sun_path);
+#ifdef HAVE_ABSTRACT_SOCKETS
+    if (abstract)
+	sockname.sun_path[0] = '\0';
+    else
+#endif
+	unlink (sockname.sun_path);
 
     if ((status = TRANS(SocketCreateListener) (ciptr,
 	(struct sockaddr *) &sockname, namelen, flags)) < 0)
@@ -1140,6 +1171,10 @@
         return TRANS_CREATE_LISTENER_FAILED;
     }
 
+#ifdef HAVE_ABSTRACT_SOCKETS
+    if (ciptr->transptr->flags & TRANS_ABSTRACT)
+	sockname.sun_path[0] = '@';
+#endif
     ciptr->family = sockname.sun_family;
     ciptr->addrlen = namelen;
     memcpy (ciptr->addr, &sockname, ciptr->addrlen);
@@ -1148,6 +1183,7 @@
 
     return 0;
 }
+#undef ABSTRACTARG
 
 
 static int
@@ -1165,12 +1201,20 @@
 
     PRMSG (3, "SocketUNIXResetListener(%p,%d)\n", ciptr, ciptr->fd, 0);
 
-    if (stat (unsock->sun_path, &statb) == -1 ||
+    if (
+#ifdef HAVE_ABSTRACT_SOCKETS
+	! (ciptr->transptr->flags & TRANS_ABSTRACT) && (
+#endif
+	stat (unsock->sun_path, &statb) == -1 ||
         ((statb.st_mode & S_IFMT) !=
 #if (defined (sun) && defined(SVR4)) || defined(NCR) || defined(SCO325) || !defined(S_IFSOCK)
-	  		S_IFIFO))
+	  		S_IFIFO
 #else
-			S_IFSOCK))
+			S_IFSOCK
+#endif
+				))
+#ifdef HAVE_ABSTRACT_SOCKETS
+	)
 #endif
     {
 	int oldUmask = umask (0);
@@ -1353,6 +1397,10 @@
         return NULL;
     }
 
+    /*
+     * if the socket is abstract, we already modified the address to have a
+     * @ instead of the initial NUL, so no need to do that again here.
+     */
 
     newciptr->addrlen = ciptr->addrlen;
     memcpy (newciptr->addr, ciptr->addr, newciptr->addrlen);
@@ -1951,6 +1999,12 @@
     int			old_namelen;
 #endif
 
+#ifdef HAVE_ABSTRACT_SOCKETS
+    int abstract = ciptr->transptr->flags & TRANS_ABSTRACT;
+#define ABSTRACTARG , abstract
+#else
+#define ABSTRACTARG 
+#endif
 
     PRMSG (2,"SocketUNIXConnect(%d,%s,%s)\n", ciptr->fd, host, port);
     
@@ -1988,7 +2042,7 @@
     
     sockname.sun_family = AF_UNIX;
 
-    if (set_sun_path(port, UNIX_PATH, sockname.sun_path) != 0) {
+    if (set_sun_path(port, UNIX_PATH, sockname.sun_path ABSTRACTARG) != 0) {
 	PRMSG (1, "SocketUNIXConnect: path too long\n", 0, 0, 0);
 	return TRANS_CONNECT_FAILED;
     }
@@ -2006,7 +2060,7 @@
      * This is gross, but it was in Xlib
      */
     old_sockname.sun_family = AF_UNIX;
-    if (set_sun_path(port, OLD_UNIX_PATH, old_sockname.sun_path) != 0) {
+    if (set_sun_path(port, OLD_UNIX_PATH, old_sockname.sun_path ABSTRACTARG) != 0) {
 	PRMSG (1, "SocketUNIXConnect: path too long\n", 0, 0, 0);
 	return TRANS_CONNECT_FAILED;
     }
@@ -2014,6 +2068,19 @@
 	sizeof (old_sockname.sun_family);
 #endif
 
+#ifdef HAVE_ABSTRACT_SOCKETS
+    /*
+     * Adjust the socket path if using abstract sockets.
+     * Done here because otherwise all the strlen() calls above would fail.
+     */
+
+    if (abstract) {
+	sockname.sun_path[0] = '\0';
+#if defined(hpux) && defined(X11_t)
+	old_sockname.sun_path[0] = '\0';
+#endif
+    }
+#endif
 
     /*
      * Do the connect()
@@ -2051,12 +2118,21 @@
 	     * should try again.
 	     */
 
-	    if (olderrno == ENOENT || olderrno == EINTR)
-		return TRANS_TRY_CONNECT_AGAIN;
-	    else if (olderrno == EWOULDBLOCK || olderrno == EINPROGRESS)
+	    if (olderrno == EWOULDBLOCK || olderrno == EINPROGRESS)
 		return TRANS_IN_PROGRESS;
-	    else
-	    {
+	    else if (olderrno == EINTR)
+		return TRANS_TRY_CONNECT_AGAIN;
+	    else if (olderrno == ENOENT) {
+#ifdef HAVE_ABSTRACT_SOCKETS
+		/*
+		* If opening as abstract socket failed, try again "normally"
+		*/
+		if (abstract)
+		    ciptr->transptr->flags &= ~(TRANS_ABSTRACT);
+#endif
+		return TRANS_TRY_CONNECT_AGAIN;
+	    }
+	    else {
 		PRMSG (2,"SocketUNIXConnect: Can't connect: errno = %d\n",
 		       EGET(),0, 0);
 
@@ -2079,14 +2155,20 @@
         return TRANS_CONNECT_FAILED;
     }
 
+#ifdef HAVE_ABSTRACT_SOCKETS
+    if (abstract)
+	sockname.sun_path[0] = '@';
+#endif
+
     ciptr->family = AF_UNIX;
     ciptr->addrlen = namelen;
     ciptr->peeraddrlen = namelen;
     memcpy (ciptr->addr, &sockname, ciptr->addrlen);
     memcpy (ciptr->peeraddr, &sockname, ciptr->peeraddrlen);
-    
+
     return 0;
 }
+#undef ABSTRACTARG
 
 #endif /* UNIXCONN */
 
@@ -2095,7 +2177,6 @@
 
 static int
 TRANS(SocketBytesReadable) (XtransConnInfo ciptr, BytesReadable_t *pend)
-
 {
     PRMSG (2,"SocketBytesReadable(%p,%d,%p)\n",
 	ciptr, ciptr->fd, pend);
@@ -2124,7 +2205,6 @@
 
 static int
 TRANS(SocketRead) (XtransConnInfo ciptr, char *buf, int size)
-
 {
     PRMSG (2,"SocketRead(%d,%p,%d)\n", ciptr->fd, buf, size);
 
@@ -2144,7 +2224,6 @@
 
 static int
 TRANS(SocketWrite) (XtransConnInfo ciptr, char *buf, int size)
-
 {
     PRMSG (2,"SocketWrite(%d,%p,%d)\n", ciptr->fd, buf, size);
 
@@ -2164,7 +2243,6 @@
 
 static int
 TRANS(SocketReadv) (XtransConnInfo ciptr, struct iovec *buf, int size)
-
 {
     PRMSG (2,"SocketReadv(%d,%p,%d)\n", ciptr->fd, buf, size);
 
@@ -2174,7 +2252,6 @@
 
 static int
 TRANS(SocketWritev) (XtransConnInfo ciptr, struct iovec *buf, int size)
-
 {
     PRMSG (2,"SocketWritev(%d,%p,%d)\n", ciptr->fd, buf, size);
 
@@ -2184,7 +2261,6 @@
 
 static int
 TRANS(SocketDisconnect) (XtransConnInfo ciptr)
-
 {
     PRMSG (2,"SocketDisconnect(%p,%d)\n", ciptr, ciptr->fd, 0);
 
@@ -2203,7 +2279,6 @@
 #ifdef TCPCONN
 static int
 TRANS(SocketINETClose) (XtransConnInfo ciptr)
-
 {
     PRMSG (2,"SocketINETClose(%p,%d)\n", ciptr, ciptr->fd, 0);
 
@@ -2224,7 +2299,6 @@
 #ifdef UNIXCONN
 static int
 TRANS(SocketUNIXClose) (XtransConnInfo ciptr)
-
 {
     /*
      * If this is the server side, then once the socket is closed,
@@ -2243,7 +2317,11 @@
        && sockname->sun_family == AF_UNIX
        && sockname->sun_path[0])
     {
-	if (!(ciptr->flags & TRANS_NOUNLINK))
+	if (!(ciptr->flags & TRANS_NOUNLINK
+#ifdef HAVE_ABSTRACT_SOCKETS
+		    || ciptr->transptr->flags & TRANS_ABSTRACT
+#endif
+		    ))
 		unlink (sockname->sun_path);
     }
 
@@ -2252,7 +2330,6 @@
 
 static int
 TRANS(SocketUNIXCloseForCloning) (XtransConnInfo ciptr)
-
 {
     /*
      * Don't unlink path.
@@ -2410,7 +2487,11 @@
 Xtransport	TRANS(SocketLocalFuncs) = {
 	/* Socket Interface */
 	"local",
+#ifdef HAVE_ABSTRACT_SOCKETS
+	TRANS_ABSTRACT,
+#else
 	0,
+#endif
 #ifdef TRANS_CLIENT
 	TRANS(SocketOpenCOTSClient),
 #endif /* TRANS_CLIENT */
@@ -2456,7 +2537,7 @@
 Xtransport	TRANS(SocketUNIXFuncs) = {
 	/* Socket Interface */
 	"unix",
-#if !defined(LOCALCONN)
+#if !defined(LOCALCONN) && !defined(HAVE_ABSTRACT_SOCKETS)
         TRANS_ALIAS,
 #else
 	0,
@@ -2502,3 +2583,6 @@
 	};
 
 #endif /* UNIXCONN */
+
+/* vim:set ts=8 sw=4: */
+
Index: lib/xtrans/configure.ac
===================================================================
RCS file: /cvs/xorg/lib/xtrans/configure.ac,v
retrieving revision 1.14
diff -u -r1.14 configure.ac
--- lib/xtrans/configure.ac	15 Dec 2005 00:24:36 -0000	1.14
+++ lib/xtrans/configure.ac	17 Mar 2006 04:08:43 -0000
@@ -48,5 +48,15 @@
 
 XORG_RELEASE_VERSION
 
+case $target in
+	*linux*)
+		abstract_socket_define="-DHAVE_ABSTRACT_SOCKETS"
+		;;
+	*)
+		abstract_socket_define=""
+esac
+
+AC_SUBST(abstract_socket_define)
+
 AC_OUTPUT([Makefile
            xtrans.pc])
Index: lib/xtrans/xtrans.pc.in
===================================================================
RCS file: /cvs/xorg/lib/xtrans/xtrans.pc.in,v
retrieving revision 1.5
diff -u -r1.5 xtrans.pc.in
--- lib/xtrans/xtrans.pc.in	2 Jul 2005 18:00:50 -0000	1.5
+++ lib/xtrans/xtrans.pc.in	17 Mar 2006 04:08:43 -0000
@@ -6,4 +6,4 @@
 Name: XTrans
 Description: Abstract network code for X
 Version: @PACKAGE_VERSION@
-Cflags: -I${includedir} -D_BSD_SOURCE @fchown_define@ @sticky_bit_define@
+Cflags: -I${includedir} -D_BSD_SOURCE @fchown_define@ @sticky_bit_define@ @abstract_socket_define@