From: Damjan Jovanovic <damjan.jov@gmail.com>
Subject: [PATCH 5/7] winex11.drv: use the correct drop effect for WM_DROPFILES (try 3)
Message-Id: <CAJm2B-k0LdCR7-c4UvX_oEO80OS7g-WZY20qJGuFVp1DyPLyFg@mail.gmail.com>
Date: Sat, 18 Jul 2015 10:43:05 +0200

Tests show that for a window to indicate it will accept a file drop or
to actually accept it, it must have WS_EX_ACCEPTFILES in its style,
contain DROPEFFECT_COPY, and be offered the HDROP format.

Try 2 and 3: no changes.

Damjan Jovanovic
---
 dlls/winex11.drv/xdnd.c | 91 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 60 insertions(+), 31 deletions(-)

diff --git a/dlls/winex11.drv/xdnd.c b/dlls/winex11.drv/xdnd.c
index a177957..cdb79ad 100644
--- a/dlls/winex11.drv/xdnd.c
+++ b/dlls/winex11.drv/xdnd.c
@@ -67,7 +67,8 @@ static HWND XDNDLastTargetWnd;
 /* might be an ancestor of XDNDLastTargetWnd */
 static HWND XDNDLastDropTargetWnd;
 
-static void X11DRV_XDND_SendDropFiles(HWND hwnd);
+static BOOL X11DRV_XDND_HasHDROP(void);
+static HRESULT X11DRV_XDND_SendDropFiles(HWND hwnd);
 static void X11DRV_XDND_FreeDragDropOp(void);
 
 
@@ -346,8 +347,15 @@ void X11DRV_XDND_PositionEvent( HWND hWnd, XClientMessageEvent *event )
 
     if (XDNDAccepted)
         accept = 1;
-    if (GetWindowLongW( hWnd, GWL_EXSTYLE ) & WS_EX_ACCEPTFILES)
+    else if (dropTarget == NULL &&
+            (GetWindowLongW( hWnd, GWL_EXSTYLE ) & WS_EX_ACCEPTFILES) &&
+            (effect & DROPEFFECT_COPY) &&
+            X11DRV_XDND_HasHDROP())
+    {
         accept = 1;
+        effect = DROPEFFECT_COPY;
+        XDNDDropEffect = effect;
+    }
 
     TRACE("action req: %ld accept(%d) at x(%d),y(%d)\n",
           event->data.l[4], accept, XDNDxy.x, XDNDxy.y);
@@ -419,8 +427,17 @@ void X11DRV_XDND_DropEvent( HWND hWnd, XClientMessageEvent *event )
     {
         /* Only send WM_DROPFILES if there is no drop target. Doing both
          * causes winamp to duplicate the dropped files (#29081) */
-        if (GetWindowLongW( hWnd, GWL_EXSTYLE ) & WS_EX_ACCEPTFILES)
-            X11DRV_XDND_SendDropFiles( hWnd );
+        if ((GetWindowLongW( hWnd, GWL_EXSTYLE ) & WS_EX_ACCEPTFILES) &&
+                (effect & DROPEFFECT_COPY) &&
+                X11DRV_XDND_HasHDROP())
+        {
+            HRESULT hr = X11DRV_XDND_SendDropFiles( hWnd );
+            if (SUCCEEDED(hr))
+            {
+                accept = 1;
+                effect = DROPEFFECT_COPY;
+            }
+        }
     }
 
     X11DRV_XDND_FreeDragDropOp();
@@ -467,12 +484,12 @@ void X11DRV_XDND_LeaveEvent( HWND hWnd, XClientMessageEvent *event )
 
 
 /**************************************************************************
- * X11DRV_XDND_SendDropFiles
+ * X11DRV_XDND_HasHDROP
  */
-static void X11DRV_XDND_SendDropFiles(HWND hwnd)
+static BOOL X11DRV_XDND_HasHDROP(void)
 {
-    DWORD i;
     BOOL found = FALSE;
+    DWORD i;
 
     /* Find CF_HDROP type if any */
     for (i = 0; i < XDNDTypeListSize; i++)
@@ -485,35 +502,47 @@ static void X11DRV_XDND_SendDropFiles(HWND hwnd)
         }
     }
 
-    if (found)
-    {
-        HRESULT hr;
-        FORMATETC formatEtc;
-        STGMEDIUM stgMedium;
+    return found;
+}
 
-        formatEtc.cfFormat = CF_HDROP;
-        formatEtc.dwAspect = DVASPECT_CONTENT;
-        formatEtc.ptd = NULL;
-        formatEtc.tymed = TYMED_HGLOBAL;
 
-        hr = IDataObject_GetData(&XDNDDataObject, &formatEtc, &stgMedium);
-        if (SUCCEEDED(hr))
+/**************************************************************************
+ * X11DRV_XDND_SendDropFiles
+ */
+static HRESULT X11DRV_XDND_SendDropFiles(HWND hwnd)
+{
+    HRESULT hr;
+    FORMATETC formatEtc;
+    STGMEDIUM stgMedium;
+
+    formatEtc.cfFormat = CF_HDROP;
+    formatEtc.dwAspect = DVASPECT_CONTENT;
+    formatEtc.ptd = NULL;
+    formatEtc.tymed = TYMED_HGLOBAL;
+
+    hr = IDataObject_GetData(&XDNDDataObject, &formatEtc, &stgMedium);
+    if (SUCCEEDED(hr))
+    {
+        DROPFILES *lpDrop = GlobalLock(stgMedium.u.hGlobal);
+        lpDrop->pt.x = XDNDxy.x;
+        lpDrop->pt.y = XDNDxy.y;
+        lpDrop->fNC  = !ScreenToClient(hwnd, &lpDrop->pt);
+        TRACE("Sending WM_DROPFILES: hWnd=0x%p, fNC=%d, x=%d, y=%d, files=%p(%s)\n", hwnd,
+                lpDrop->fNC, lpDrop->pt.x, lpDrop->pt.y, ((char*)lpDrop) + lpDrop->pFiles,
+                debugstr_w((WCHAR*)(((char*)lpDrop) + lpDrop->pFiles)));
+        GlobalUnlock(stgMedium.u.hGlobal);
+
+        if (PostMessageW(hwnd, WM_DROPFILES, (WPARAM)stgMedium.u.hGlobal, 0))
+            hr = S_OK;
+        else
         {
-            DROPFILES *lpDrop = GlobalLock(stgMedium.u.hGlobal);
-            lpDrop->pt.x = XDNDxy.x;
-            lpDrop->pt.y = XDNDxy.y;
-            lpDrop->fNC  = !ScreenToClient(hwnd, &lpDrop->pt);
-            TRACE("Sending WM_DROPFILES: hWnd=0x%p, fNC=%d, x=%d, y=%d, files=%p(%s)\n", hwnd,
-                    lpDrop->fNC, lpDrop->pt.x, lpDrop->pt.y, ((char*)lpDrop) + lpDrop->pFiles,
-                    debugstr_w((WCHAR*)(((char*)lpDrop) + lpDrop->pFiles)));
-            GlobalUnlock(stgMedium.u.hGlobal);
-
-            if (!PostMessageW(hwnd, WM_DROPFILES, (WPARAM)stgMedium.u.hGlobal, 0))
-                GlobalFree(stgMedium.u.hGlobal);
+            hr = HRESULT_FROM_WIN32(GetLastError());
+            GlobalFree(stgMedium.u.hGlobal);
         }
-        else
-            ERR("fetching CF_HDROP data for WM_DROPFILES failed, hr=0x%08x\n", hr);
     }
+    else
+        ERR("fetching CF_HDROP data for WM_DROPFILES failed, hr=0x%08x\n", hr);
+    return hr;
 }