hw/xwin: Improve choice of display name used by internal clients

Choose the display name used to connect to internal clients and exported into
environment of processes started from the traymenu so that it uses a transport
we know is working

This should mean the server can start correctly with -multiwindow and/or
-clipboard and any two of -nolisten inet6, -nolisten inet and -nolisten unix
(the server will correctly refuse to start if all 3 are used, as it must be
listening on at least one socket)

v2:
Place prototype for winGetDisplayName() in windisplay.h, and include it where
needed.

v3:
Include xwin-config.h, so that _XSERVER64 is defined, just in case anything
relies on that.

v4:
Replace grovelling around in the server's list of listeners with new Xtrans
TransIsListening() interface, added in Xtrans 1.3.3

See also [1]

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=10725

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net>
Reviewed-by: Colin Harrison <colin.harrison@virgin.net>

7 files changed, 111 insertions, 9 deletions

diff --git a/hw/xwin/Makefile.am b/hw/xwin/Makefile.am
index 5908dfce4..326ffa03d 100644
--- a/hw/xwin/Makefile.am
+++ b/hw/xwin/Makefile.am
@@ -126,6 +126,8 @@ SRCS =	InitInput.c \
 	winprefs.h \
 	winresource.h \
 	winwindow.h \
+	windisplay.c \
+	windisplay.h \
 	XWin.rc \
 	$(top_srcdir)/mi/miinitext.c \
 	$(SRCS_CLIPBOARD) \
diff --git a/hw/xwin/winclipboardthread.c b/hw/xwin/winclipboardthread.c
index 33595be7f..e70896081 100644
--- a/hw/xwin/winclipboardthread.c
+++ b/hw/xwin/winclipboardthread.c
@@ -38,6 +38,7 @@
 #include <sys/types.h>
 #include <signal.h>
 #include "winclipboard.h"
+#include "windisplay.h"
 #ifdef __CYGWIN__
 #include <errno.h>
 #endif
@@ -157,7 +158,7 @@ winClipboardProc(void *pvNotUsed)
      * for all screens on the display.  That is why there is only
      * one clipboard client thread.
      */
-    snprintf(szDisplay, 512, "127.0.0.1:%s.0", display);
+    winGetDisplayName(szDisplay, 0);
 
     /* Print the display connection string */
     ErrorF("winClipboardProc - DISPLAY=%s\n", szDisplay);
diff --git a/hw/xwin/windisplay.c b/hw/xwin/windisplay.c
new file mode 100644
index 000000000..17f0c7789
--- /dev/null
+++ b/hw/xwin/windisplay.c
@@ -0,0 +1,64 @@
+/*
+ * File: windisplay.c
+ * Purpose: Retrieve server display name
+ *
+ * Copyright (C) Jon TURNEY 2009
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifdef HAVE_XWIN_CONFIG_H
+#include <xwin-config.h>
+#endif
+
+#include <opaque.h>             // for display
+#include "windisplay.h"
+#include "winmsg.h"
+
+#define XSERV_t
+#define TRANS_SERVER
+#include <X11/Xtrans/Xtrans.h>
+
+/*
+  Generate a display name string referring to the display of this server,
+  using a transport we know is enabled
+*/
+
+void
+winGetDisplayName(char *szDisplay, unsigned int screen)
+{
+    if (_XSERVTransIsListening("local")) {
+        snprintf(szDisplay, 512, ":%s.%d", display, screen);
+    }
+    else if (_XSERVTransIsListening("inet")) {
+        snprintf(szDisplay, 512, "127.0.0.1:%s.%d", display, screen);
+    }
+    else if (_XSERVTransIsListening("inet6")) {
+        snprintf(szDisplay, 512, "::1:%s.%d", display, screen);
+    }
+    else {
+        // this can't happen!
+        ErrorF("winGetDisplay: Don't know what to use for DISPLAY\n");
+        snprintf(szDisplay, 512, "localhost:%s.%d", display, screen);
+    }
+
+    winDebug("winGetDisplay: DISPLAY=%s\n", szDisplay);
+}
diff --git a/hw/xwin/windisplay.h b/hw/xwin/windisplay.h
new file mode 100644
index 000000000..d1d4549bf
--- /dev/null
+++ b/hw/xwin/windisplay.h
@@ -0,0 +1,34 @@
+/*
+ * File: windisplay.h
+ * Purpose: Interface to retrieve server display name
+ *
+ * Copyright (C) Jon TURNEY 2009
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifndef WINDISPLAY_H
+#define WINDISPLAY_H
+
+void
+winGetDisplayName(char *szDisplay, unsigned int screen);
+
+#endif /* !WINDISPLAY_H */
diff --git a/hw/xwin/winmsg.h b/hw/xwin/winmsg.h
index b638f2cb3..6c96c4070 100644
--- a/hw/xwin/winmsg.h
+++ b/hw/xwin/winmsg.h
@@ -30,6 +30,8 @@
  * Authors: Alexander Gottwald	
  */
 
+#include <X11/Xwindows.h>
+
 /*
  * Function prototypes
  */
diff --git a/hw/xwin/winmultiwindowwm.c b/hw/xwin/winmultiwindowwm.c
index 618e38121..e17a9502d 100644
--- a/hw/xwin/winmultiwindowwm.c
+++ b/hw/xwin/winmultiwindowwm.c
@@ -61,6 +61,7 @@
 #include "pixmapstr.h"
 #include "windowstr.h"
 #include "winglobals.h"
+#include "windisplay.h"
 
 #ifdef XWIN_MULTIWINDOWEXTWM
 #include <X11/extensions/windowswmstr.h>
@@ -1053,8 +1054,7 @@ winMultiWindowXMsgProc(void *pArg)
     }
 
     /* Setup the display connection string x */
-    snprintf(pszDisplay,
-             512, "127.0.0.1:%s.%d", display, (int) pProcArg->dwScreen);
+    winGetDisplayName(pszDisplay, (int) pProcArg->dwScreen);
 
     /* Print the display connection string */
     ErrorF("winMultiWindowXMsgProc - DISPLAY=%s\n", pszDisplay);
@@ -1446,8 +1446,7 @@ winInitMultiWindowWM(WMInfoPtr pWMInfo, WMProcArgPtr pProcArg)
     }
 
     /* Setup the display connection string x */
-    snprintf(pszDisplay,
-             512, "127.0.0.1:%s.%d", display, (int) pProcArg->dwScreen);
+    winGetDisplayName(pszDisplay, (int) pProcArg->dwScreen);
 
     /* Print the display connection string */
     ErrorF("winInitMultiWindowWM - DISPLAY=%s\n", pszDisplay);
diff --git a/hw/xwin/winprefs.c b/hw/xwin/winprefs.c
index f386facdd..53abc163f 100644
--- a/hw/xwin/winprefs.c
+++ b/hw/xwin/winprefs.c
@@ -44,6 +44,7 @@
 #include <shellapi.h>
 
 #include "winprefs.h"
+#include "windisplay.h"
 #include "winmultiwindowclass.h"
 
 /* Where will the custom menu commands start counting from? */
@@ -712,15 +713,14 @@ LoadPreferences(void)
 
     /* Setup a DISPLAY environment variable, need to allocate on heap */
     /* because putenv doesn't copy the argument... */
-    snprintf(szDisplay, 512, "DISPLAY=127.0.0.1:%s.0", display);
-    szEnvDisplay = (char *) (malloc(strlen(szDisplay) + 1));
+    winGetDisplayName(szDisplay, 0);
+    szEnvDisplay = (char *) (malloc(strlen(szDisplay) + strlen("DISPLAY=") + 1));
     if (szEnvDisplay) {
-        strcpy(szEnvDisplay, szDisplay);
+        snprintf(szEnvDisplay, 512, "DISPLAY=%s", szDisplay);
         putenv(szEnvDisplay);
     }
 
     /* Replace any "%display%" in menu commands with display string */
-    snprintf(szDisplay, 512, "127.0.0.1:%s.0", display);
     for (i = 0; i < pref.menuItems; i++) {
         for (j = 0; j < pref.menu[i].menuItems; j++) {
             if (pref.menu[i].menuItem[j].cmd == CMD_EXEC) {