Cygwin/X: Improve choice of display name used by internal clients

Choose display name used to connect internal clients and exported into
environment of processes started by 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)

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>

8 files changed, 89 insertions, 20 deletions

diff --git a/hw/xwin/Makefile.am b/hw/xwin/Makefile.am
index c01e485a7..6d8f82371 100644
--- a/hw/xwin/Makefile.am
+++ b/hw/xwin/Makefile.am
@@ -120,6 +120,7 @@ SRCS =	InitInput.c \
 	winpriv.h \
 	winresource.h \
 	winwindow.h \
+	windisplay.c \
 	XWin.rc \
 	$(top_srcdir)/Xext/dpmsstubs.c \
 	$(top_srcdir)/Xi/stubs.c \
diff --git a/hw/xwin/win.h b/hw/xwin/win.h
index 9ab8ed976..259ff43d1 100644
--- a/hw/xwin/win.h
+++ b/hw/xwin/win.h
@@ -1453,6 +1453,13 @@ Bool
 winInitCursor (ScreenPtr pScreen);
 
 /*
+ * windisplay.c
+ */
+
+void
+winGetDisplayName(char *szDisplay, unsigned int screen);
+
+/*
  * END DDX and DIX Function Prototypes
  */
 
diff --git a/hw/xwin/winclipboardthread.c b/hw/xwin/winclipboardthread.c
index 28c7372b8..9788d883b 100644
--- a/hw/xwin/winclipboardthread.c
+++ b/hw/xwin/winclipboardthread.c
@@ -163,10 +163,7 @@ 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..ce111abda
--- /dev/null
+++ b/hw/xwin/windisplay.c
@@ -0,0 +1,56 @@
+/*
+ * 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.
+ *
+ */
+
+#include <opaque.h>  // for display
+#include "win.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 (TransIsListening("local"))
+    {
+      snprintf(szDisplay, 512, ":%s.%d", display, screen);
+    }
+  else if (TransIsListening("inet"))
+    {
+      snprintf(szDisplay, 512, "127.0.0.1:%s.%d", display, screen);
+    }
+  else if (TransIsListening("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);
+    }
+
+  ErrorF ("winGetDisplay: DISPLAY=%s\n", szDisplay);
+}
diff --git a/hw/xwin/winmultiwindowwm.c b/hw/xwin/winmultiwindowwm.c
index c4f11ba6f..6c2812c6f 100644
--- a/hw/xwin/winmultiwindowwm.c
+++ b/hw/xwin/winmultiwindowwm.c
@@ -136,7 +136,6 @@ typedef struct _XMsgProcArgRec {
  * References to external symbols
  */
 
-extern char *display;
 extern void ErrorF (const char* /*f*/, ...);
 
 /*
@@ -934,8 +933,7 @@ winMultiWindowXMsgProc (void *pArg)
   XSetIOErrorHandler (winMultiWindowXMsgProcIOErrorHandler);
 
   /* 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);
@@ -1317,11 +1315,7 @@ winInitMultiWindowWM (WMInfoPtr pWMInfo, WMProcArgPtr pProcArg)
   XSetIOErrorHandler (winMultiWindowWMIOErrorHandler);
 
   /* 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 93901cac7..14409ecae 100644
--- a/hw/xwin/winprefs.c
+++ b/hw/xwin/winprefs.c
@@ -69,10 +69,6 @@ extern HICON		g_hSmallIconX;
 /* Currently in use command ID, incremented each new menu item created */
 static int g_cmdid = STARTMENUID;
 
-
-/* Defined in DIX */
-extern char *display;
-
 /* Local function to handle comma-ified icon names */
 static HICON
 LoadImageComma (char *fname, int sx, int sy, int flags);
@@ -780,16 +776,15 @@ 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++)
diff --git a/include/os.h b/include/os.h
index 453ab82c7..9054eed57 100644
--- a/include/os.h
+++ b/include/os.h
@@ -114,6 +114,8 @@ extern _X_EXPORT int WriteToClient(ClientPtr /*who*/, int /*count*/, const void*
 
 extern _X_EXPORT void ResetOsBuffers(void);
 
+extern _X_EXPORT int TransIsListening(char *protocol);
+
 extern _X_EXPORT void InitConnectionLimits(void);
 
 extern _X_EXPORT void NotifyParentProcess(void);
diff --git a/os/connection.c b/os/connection.c
index 3ff93bbb6..5ea55ae4e 100644
--- a/os/connection.c
+++ b/os/connection.c
@@ -270,6 +270,23 @@ lookup_trans_conn (int fd)
     return (NULL);
 }
 
+int
+TransIsListening(char *protocol)
+{
+  /* look for this transport in the list of listeners */
+  int i;
+  for (i = 0; i < ListenTransCount; i++)
+    {
+      if (!strcmp(protocol, ListenTransConns[i]->transptr->TransName))
+        {
+          return 1;
+        }
+    }
+
+  return 0;
+}
+
+
 /* Set MaxClients and lastfdesc, and allocate ConnectionTranslation */
 
 void