From 0a0c1bd93259c208184d6ad974ba55658191af0c Mon Sep 17 00:00:00 2001
From: Jon Turney <jon.turney@dronecode.org.uk>
Date: Fri, 26 Feb 2016 18:03:04 +0000
Subject: [PATCH] hw/xwin: Fix a crash trying to reload window icons when not
 in multiwindow mode

ReloadEnumWindowsProc() accesses window privates, which are only valid in
multiwindow mode, but is called in all modes.

Fix this potential crash by not doing this unless in multiwindow mode.

Reproduction steps:
1/ XWin -mwextwm
2/ Run a client which creates an X window e.g. xterm
3/ Right click on notification area icon, and choose 'Reload .XWinrc' from the menu

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>
Reviewed-by: Colin Harrison <colin.harrison@virgin.net>
---
 hw/xwin/winmultiwindowwndproc.c |  2 +-
 hw/xwin/winprefs.c              | 29 ++++++++++++++++++-----------
 hw/xwin/winprefs.h              |  9 ++++++---
 hw/xwin/winwndproc.c            |  2 +-
 4 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/hw/xwin/winmultiwindowwndproc.c b/hw/xwin/winmultiwindowwndproc.c
index 656f6c2da..3f47fec65 100644
--- a/hw/xwin/winmultiwindowwndproc.c
+++ b/hw/xwin/winmultiwindowwndproc.c
@@ -428,7 +428,7 @@ winTopLevelWindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
         /*
          * Any window menu items go through here
          */
-        if (HandleCustomWM_COMMAND(hwnd, LOWORD(wParam))) {
+        if (HandleCustomWM_COMMAND(hwnd, LOWORD(wParam), s_pScreenPriv)) {
             /* Don't pass customized menus to DefWindowProc */
             return 0;
         }
diff --git a/hw/xwin/winprefs.c b/hw/xwin/winprefs.c
index a180a9e8f..65115ec5b 100644
--- a/hw/xwin/winprefs.c
+++ b/hw/xwin/winprefs.c
@@ -206,18 +206,21 @@ ReloadEnumWindowsProc(HWND hwnd, LPARAM lParam)
  * Set custom icons and menus again.
  */
 static void
-ReloadPrefs(void)
+ReloadPrefs(winPrivScreenPtr pScreenPriv)
 {
     int i;
 
 #ifdef XWIN_MULTIWINDOW
+    winScreenInfo *pScreenInfo = pScreenPriv->pScreenInfo;
+
     /* First, iterate over all windows, deleting their icons and custom menus.
      * This is really only needed because winDestroyIcon() will try to
      * destroy the old global icons, which will have changed.
      * It is probably better to set a windows USER_DATA to flag locally defined
      * icons, and use that to accurately know when to destroy old icons.
      */
-    EnumThreadWindows(g_dwCurrentThreadID, ReloadEnumWindowsProc, FALSE);
+    if (pScreenInfo->fMultiWindow)
+        EnumThreadWindows(g_dwCurrentThreadID, ReloadEnumWindowsProc, FALSE);
 #endif
 
     /* Now, free/clear all info from our prefs structure */
@@ -262,12 +265,12 @@ ReloadPrefs(void)
     g_hSmallIconX = NULL;
 
 #ifdef XWIN_MULTIWINDOW
-    winInitGlobalIcons();
-#endif
+    if (pScreenInfo->fMultiWindow) {
+        winInitGlobalIcons();
 
-#ifdef XWIN_MULTIWINDOW
-    /* Rebuild the icons and menus */
-    EnumThreadWindows(g_dwCurrentThreadID, ReloadEnumWindowsProc, TRUE);
+        /* Rebuild the icons and menus */
+        EnumThreadWindows(g_dwCurrentThreadID, ReloadEnumWindowsProc, TRUE);
+    }
 #endif
 
     /* Whew, done */
@@ -303,7 +306,7 @@ HandleCustomWM_INITMENU(HWND hwnd, HMENU hmenu)
  * Return TRUE if command is proccessed, FALSE otherwise.
  */
 Bool
-HandleCustomWM_COMMAND(HWND hwnd, int command)
+HandleCustomWM_COMMAND(HWND hwnd, WORD command, winPrivScreenPtr pScreenPriv)
 {
     int i, j;
     MENUPARSED *m;
@@ -383,13 +386,17 @@ HandleCustomWM_COMMAND(HWND hwnd, int command)
                                      HWND_TOPMOST,
                                      0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE);
 #if XWIN_MULTIWINDOW
-                    /* Reflect the changed Z order */
-                    winReorderWindowsMultiWindow();
+                    {
+                        winScreenInfo *pScreenInfo = pScreenPriv->pScreenInfo;
+                        if (pScreenInfo->fMultiWindow)
+                            /* Reflect the changed Z order */
+                            winReorderWindowsMultiWindow();
+                    }
 #endif
                     return TRUE;
 
                 case CMD_RELOAD:
-                    ReloadPrefs();
+                    ReloadPrefs(pScreenPriv);
                     return TRUE;
 
                 default:
diff --git a/hw/xwin/winprefs.h b/hw/xwin/winprefs.h
index 8f4eb0807..936a42f22 100644
--- a/hw/xwin/winprefs.h
+++ b/hw/xwin/winprefs.h
@@ -1,5 +1,3 @@
-#if !defined(WINPREFS_H)
-#define WINPREFS_H
 /*
  * Copyright (C) 1994-2000 The XFree86 Project, Inc. All Rights Reserved.
  * Copyright (C) Colin Harrison 2005-2008
@@ -32,6 +30,9 @@
  *              Colin Harrison
  */
 
+#if !defined(WINPREFS_H)
+#define WINPREFS_H
+
 /* Need Bool */
 #include <X11/Xdefs.h>
 /* Need TRUE */
@@ -42,6 +43,8 @@
 /* Xwindows redefines PATH_MAX to at least 1024 */
 #include <X11/Xwindows.h>
 
+#include "winwindow.h"
+
 #ifndef NAME_MAX
 #define NAME_MAX PATH_MAX
 #endif
@@ -159,7 +162,7 @@ void
  HandleCustomWM_INITMENU(HWND hwnd, HMENU hmenu);
 
 Bool
- HandleCustomWM_COMMAND(HWND hwnd, int command);
+ HandleCustomWM_COMMAND(HWND hwnd, WORD command, winPrivScreenPtr pScreenPriv);
 
 int
  winIconIsOverride(HICON hicon);
diff --git a/hw/xwin/winwndproc.c b/hw/xwin/winwndproc.c
index 3df22927d..6cbd44755 100644
--- a/hw/xwin/winwndproc.c
+++ b/hw/xwin/winwndproc.c
@@ -1215,7 +1215,7 @@ winWindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 
         default:
             /* It's probably one of the custom menus... */
-            if (HandleCustomWM_COMMAND(0, LOWORD(wParam)))
+            if (HandleCustomWM_COMMAND(0, LOWORD(wParam), s_pScreenPriv))
                 return 0;
         }
         break;