Only allocate even-numbered window handles, MS Project depends on that

server/user.c

@@ -35,7 +35,7 @@ static int allocated_handles;
 
 static struct user_handle *handle_to_entry( user_handle_t handle )
 {
-    int index = ((unsigned int)handle & 0xffff) - FIRST_USER_HANDLE;
+    int index = (((unsigned int)handle & 0xffff) - FIRST_USER_HANDLE) >> 1;
     if (index < 0 || index >= nb_handles) return NULL;
     if (!handles[index].type) return NULL;
     if (((unsigned int)handle >> 16) && ((unsigned int)handle >> 16 != handles[index].generation))
@@ -46,7 +46,7 @@ static struct user_handle *handle_to_entry( user_handle_t handle )
 inline static user_handle_t entry_to_handle( struct user_handle *ptr )
 {
     int index = ptr - handles;
-    return (user_handle_t)((index + FIRST_USER_HANDLE) + (ptr->generation << 16));
+    return (user_handle_t)(((index << 1) + FIRST_USER_HANDLE) + (ptr->generation << 16));
 }
 
 inline static struct user_handle *alloc_user_entry(void)
@@ -64,7 +64,7 @@ inline static struct user_handle *alloc_user_entry(void)
         struct user_handle *new_handles;
         /* grow array by 50% (but at minimum 32 entries) */
         int growth = max( 32, allocated_handles / 2 );
-        int new_size = min( allocated_handles + growth, LAST_USER_HANDLE-FIRST_USER_HANDLE+1 );
+        int new_size = min( allocated_handles + growth, (LAST_USER_HANDLE-FIRST_USER_HANDLE+1) >> 1 );
         if (new_size <= allocated_handles) return NULL;
         if (!(new_handles = realloc( handles, new_size * sizeof(*handles) )))
             return NULL;
@@ -147,7 +147,7 @@ void *next_user_handle( user_handle_t *handle, enum user_object type )
     if (!*handle) entry = handles;
     else
     {
-        int index = ((unsigned int)*handle & 0xffff) - FIRST_USER_HANDLE;
+        int index = (((unsigned int)*handle & 0xffff) - FIRST_USER_HANDLE) >> 1;
         if (index < 0 || index >= nb_handles) return NULL;
         entry = handles + index + 1;  /* start from the next one */
     }

windows/win.c

@@ -45,7 +45,8 @@
 WINE_DEFAULT_DEBUG_CHANNEL(win);
 WINE_DECLARE_DEBUG_CHANNEL(msg);
 
-#define NB_USER_HANDLES  (LAST_USER_HANDLE - FIRST_USER_HANDLE + 1)
+#define NB_USER_HANDLES  ((LAST_USER_HANDLE - FIRST_USER_HANDLE + 1) >> 1)
+#define USER_HANDLE_TO_INDEX(hwnd) ((LOWORD(hwnd) - FIRST_USER_HANDLE) >> 1)
 
 /**********************************************************************/
 
@@ -110,7 +111,7 @@ static WND *create_window_handle( HWND parent, HWND owner, ATOM atom,
 
     USER_Lock();
 
-    index = LOWORD(handle) - FIRST_USER_HANDLE;
+    index = USER_HANDLE_TO_INDEX(handle);
     assert( index < NB_USER_HANDLES );
     user_handles[index] = win;
     win->hwndSelf   = handle;
@@ -131,7 +132,7 @@ static WND *create_window_handle( HWND parent, HWND owner, ATOM atom,
 static WND *free_window_handle( HWND hwnd )
 {
     WND *ptr;
-    WORD index = LOWORD(hwnd) - FIRST_USER_HANDLE;
+    WORD index = USER_HANDLE_TO_INDEX(hwnd);
 
     if (index >= NB_USER_HANDLES) return NULL;
     USER_Lock();
@@ -234,7 +235,7 @@ static void get_server_window_text( HWND hwnd, LPWSTR text, INT count )
 WND *WIN_GetPtr( HWND hwnd )
 {
     WND * ptr;
-    WORD index = LOWORD(hwnd) - FIRST_USER_HANDLE;
+    WORD index = USER_HANDLE_TO_INDEX(hwnd);
 
     if (index >= NB_USER_HANDLES) return NULL;