Don't bother to return partial region data in get_window_region and

dlls/x11drv/winpos.c

@@ -33,6 +33,7 @@
 #include "wingdi.h"
 #include "winuser.h"
 #include "winerror.h"
+#include "ntstatus.h"
 #include "wownt32.h"
 #include "wine/wingdi16.h"
 
@@ -138,9 +139,9 @@ static int clip_children( HWND parent, HWND last, HRGN hrgn, int whole_window )
 static HRGN get_server_visible_region( HWND hwnd, HWND top, UINT flags )
 {
     RGNDATA *data;
+    NTSTATUS status;
     HRGN ret = 0;
     size_t size = 256;
-    BOOL retry = FALSE;
 
     do
     {
@@ -151,28 +152,22 @@ static HRGN get_server_visible_region( HWND hwnd, HWND top, UINT flags )
             req->top_win = top;
             req->flags   = flags;
             wine_server_set_reply( req, data->Buffer, size );
-            if (!wine_server_call_err( req ))
+            if (!(status = wine_server_call( req )))
             {
-                if (reply->total_size <= size)
-                {
-                    size_t reply_size = wine_server_reply_size( reply );
-                    data->rdh.dwSize   = sizeof(data->rdh);
-                    data->rdh.iType    = RDH_RECTANGLES;
-                    data->rdh.nCount   = reply_size / sizeof(RECT);
-                    data->rdh.nRgnSize = reply_size;
-                    ret = ExtCreateRegion( NULL, size, data );
-                    retry = FALSE;
-                }
-                else
-                {
-                    size = reply->total_size;
-                    retry = TRUE;
-                }
+                size_t reply_size = wine_server_reply_size( reply );
+                data->rdh.dwSize   = sizeof(data->rdh);
+                data->rdh.iType    = RDH_RECTANGLES;
+                data->rdh.nCount   = reply_size / sizeof(RECT);
+                data->rdh.nRgnSize = reply_size;
+                ret = ExtCreateRegion( NULL, size, data );
             }
+            else size = reply->total_size;
         }
         SERVER_END_REQ;
         HeapFree( GetProcessHeap(), 0, data );
-    } while (retry);
+    } while (status == STATUS_BUFFER_OVERFLOW);
+
+    if (status) SetLastError( RtlNtStatusToDosError(status) );
     return ret;
 }
 

server/region.c

@@ -618,19 +618,23 @@ void set_region_rect( struct region *region, const rectangle_t *rect )
 }
 
 /* retrieve the region data for sending to the client */
-rectangle_t *get_region_data( const struct region *region, size_t *total_size )
+rectangle_t *get_region_data( const struct region *region, size_t max_size, size_t *total_size )
 {
+    const rectangle_t *data = region->rects;
+
     if (!(*total_size = region->num_rects * sizeof(rectangle_t)))
     {
         /* return a single empty rect for empty regions */
         *total_size = sizeof(empty_rect);
-        return memdup( &empty_rect, sizeof(empty_rect) );
+        data = &empty_rect;
     }
-    return memdup( region->rects, *total_size );
+    if (max_size >= *total_size) return memdup( data, *total_size );
+    set_error( STATUS_BUFFER_OVERFLOW );
+    return NULL;
 }
 
 /* retrieve the region data for sending to the client and free the region at the same time */
-rectangle_t *get_region_data_and_free( struct region *region, size_t *total_size )
+rectangle_t *get_region_data_and_free( struct region *region, size_t max_size, size_t *total_size )
 {
     rectangle_t *ret = region->rects;
 
@@ -638,7 +642,18 @@ rectangle_t *get_region_data_and_free( struct region *region, size_t *total_size
     {
         /* return a single empty rect for empty regions */
         *total_size = sizeof(empty_rect);
-        ret = memdup( &empty_rect, sizeof(empty_rect) );
+        if (max_size >= sizeof(empty_rect))
+        {
+            ret = memdup( &empty_rect, sizeof(empty_rect) );
+            free( region->rects );
+        }
+    }
+
+    if (max_size < *total_size)
+    {
+        free( region->rects );
+        set_error( STATUS_BUFFER_OVERFLOW );
+        ret = NULL;
     }
     free( region );
     return ret;

server/user.h

@@ -71,8 +71,10 @@ extern struct region *create_region( const rectangle_t *rects, unsigned int nb_r
 extern struct region *create_region_from_req_data( const void *data, size_t size );
 extern void free_region( struct region *region );
 extern void set_region_rect( struct region *region, const rectangle_t *rect );
-extern rectangle_t *get_region_data( const struct region *region, size_t *total_size );
-extern rectangle_t *get_region_data_and_free( struct region *region, size_t *total_size );
+extern rectangle_t *get_region_data( const struct region *region, size_t max_size,
+                                     size_t *total_size );
+extern rectangle_t *get_region_data_and_free( struct region *region, size_t max_size,
+                                              size_t *total_size );
 extern int is_region_empty( const struct region *region );
 extern void get_region_extents( const struct region *region, rectangle_t *rect );
 extern void offset_region( struct region *region, int x, int y );

server/window.c

@@ -1084,8 +1084,8 @@ DECL_HANDLER(get_visible_region)
 
     if ((region = get_visible_region( win, top, req->flags )))
     {
-        rectangle_t *data = get_region_data_and_free( region, &reply->total_size );
-        set_reply_data_ptr( data, min(reply->total_size,get_reply_max_size()) );
+        rectangle_t *data = get_region_data_and_free( region, get_reply_max_size(), &reply->total_size );
+        if (data) set_reply_data_ptr( data, reply->total_size );
     }
 }
 
@@ -1097,11 +1097,10 @@ DECL_HANDLER(get_window_region)
 
     if (!win) return;
 
-    reply->total_size = 0;
     if (win->win_region)
     {
-        rectangle_t *data = get_region_data( win->win_region, &reply->total_size );
-        set_reply_data_ptr( data, min( reply->total_size, get_reply_max_size() ) );
+        rectangle_t *data = get_region_data( win->win_region, get_reply_max_size(), &reply->total_size );
+        if (data) set_reply_data_ptr( data, reply->total_size );
     }
 }
 

windows/winpos.c

@@ -29,6 +29,7 @@
 #include "winbase.h"
 #include "wingdi.h"
 #include "winerror.h"
+#include "ntstatus.h"
 #include "wine/winuser16.h"
 #include "wine/server.h"
 #include "controls.h"
@@ -172,10 +173,10 @@ BOOL WINAPI GetWindowRect( HWND hwnd, LPRECT rect )
 int WINAPI GetWindowRgn ( HWND hwnd, HRGN hrgn )
 {
     int nRet = ERROR;
+    NTSTATUS status;
     HRGN win_rgn = 0;
     RGNDATA *data;
     size_t size = 256;
-    BOOL retry = FALSE;
 
     do
     {
@@ -188,31 +189,26 @@ int WINAPI GetWindowRgn ( HWND hwnd, HRGN hrgn )
         {
             req->window = hwnd;
             wine_server_set_reply( req, data->Buffer, size );
-            if (!wine_server_call_err( req ))
+            if (!(status = wine_server_call( req )))
             {
-                if (!reply->total_size) retry = FALSE;  /* no region at all */
-                else if (reply->total_size <= size)
+                size_t reply_size = wine_server_reply_size( reply );
+                if (reply_size)
                 {
-                    size_t reply_size = wine_server_reply_size( reply );
                     data->rdh.dwSize   = sizeof(data->rdh);
                     data->rdh.iType    = RDH_RECTANGLES;
                     data->rdh.nCount   = reply_size / sizeof(RECT);
                     data->rdh.nRgnSize = reply_size;
                     win_rgn = ExtCreateRegion( NULL, size, data );
-                    retry = FALSE;
-                }
-                else
-                {
-                    size = reply->total_size;
-                    retry = TRUE;
                 }
             }
+            else size = reply->total_size;
         }
         SERVER_END_REQ;
         HeapFree( GetProcessHeap(), 0, data );
-    } while (retry);
+    } while (status == STATUS_BUFFER_OVERFLOW);
 
-    if (win_rgn)
+    if (status) SetLastError( RtlNtStatusToDosError(status) );
+    else if (win_rgn)
     {
         nRet = CombineRgn( hrgn, win_rgn, 0, RGN_COPY );
         DeleteObject( win_rgn );