From 70ddd0f39d5118db72a1a4e473cbfb502f1ed9ec Mon Sep 17 00:00:00 2001
From: Alan Hourihane <alanh@fairlite.demon.co.uk>
Date: Fri, 18 Aug 2006 14:43:10 +0100
Subject: [PATCH] Fix bug #5735, Serious flaw in CygwinX clipboard integration
 prevents paste from X to Windows apps (Brett Stahlman & Colin Harrison)

---
 hw/xwin/winclipboardwndproc.c | 48 +++++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/hw/xwin/winclipboardwndproc.c b/hw/xwin/winclipboardwndproc.c
index 09a01d3c5..802a74035 100644
--- a/hw/xwin/winclipboardwndproc.c
+++ b/hw/xwin/winclipboardwndproc.c
@@ -56,6 +56,8 @@ extern void		*g_pClipboardDisplay;
 extern Window		g_iClipboardWindow;
 extern Atom		g_atomLastOwnedSelection;
 
+/* BPS - g_hwndClipboard needed for X app->Windows paste fix */
+extern HWND		g_hwndClipboard;
 
 /* 
  * Local function prototypes
@@ -141,6 +143,12 @@ winProcessXEventsTimeout (HWND hwnd, int iWindow, Display *pDisplay,
  * Process a given Windows message
  */
 
+/* BPS - Define our own message, which we'll post to ourselves to facilitate
+ * resetting the delayed rendering mechanism after each paste from X app to
+ * Windows app. TODO - Perhaps move to win.h with the other WM_USER messages.
+ */
+#define WM_USER_PASTE_COMPLETE		(WM_USER + 1003)
+
 LRESULT CALLBACK
 winClipboardWindowProc (HWND hwnd, UINT message, 
 			WPARAM wParam, LPARAM lParam)
@@ -327,8 +335,6 @@ winClipboardWindowProc (HWND hwnd, UINT message,
 	     * previous XSetSelectionOwner messages.
 	     */
 	    XSync (pDisplay, FALSE);
-
-            winDebug("winClipboardWindowProc - XSync done.\n");
 	    
 	    /* Release PRIMARY selection if owned */
 	    iReturn = XGetSelectionOwner (pDisplay, XA_PRIMARY);
@@ -527,6 +533,13 @@ winClipboardWindowProc (HWND hwnd, UINT message,
 	    SetClipboardData (CF_TEXT, NULL);
 	  }
 
+	/* BPS - Post ourselves a user message whose handler will reset the
+	 * delayed rendering mechanism after the paste is complete. This is
+	 * necessary because calling SetClipboardData() with a NULL argument
+	 * here will cause the data we just put on the clipboard to be lost!
+	 */
+	PostMessage(g_hwndClipboard, WM_USER_PASTE_COMPLETE, 0, 0);
+
 	/* Special handling for WM_RENDERALLFORMATS */
 	if (message == WM_RENDERALLFORMATS)
 	  {
@@ -544,6 +557,37 @@ winClipboardWindowProc (HWND hwnd, UINT message,
 	winDebug ("winClipboardWindowProc - WM_RENDER*FORMAT - Returning.\n");
 	return 0;
       }
+    /* BPS - This WM_USER message is posted by us. It gives us the opportunity
+     * to reset the delayed rendering mechanism after each and every paste
+     * from an X app to a Windows app. Without such a mechanism, subsequent
+     * changes of selection in the X app owning the selection are not
+     * reflected in pastes into Windows apps, since Windows won't send us the
+     * WM_RENDERFORMAT message unless someone has set changed data (or NULL)
+     * on the clipboard. */
+    case WM_USER_PASTE_COMPLETE:
+      {
+	if (hwnd != GetClipboardOwner ())
+	  /* In case we've lost the selection since posting the message */
+	  return 0;
+	winDebug ("winClipboardWindowProc - WM_USER_PASTE_COMPLETE\n");
+
+	/* Set up for another delayed rendering callback */
+	OpenClipboard (g_hwndClipboard);
+
+	/* Take ownership of the Windows clipboard */
+	EmptyClipboard ();
+
+	/* Advertise Unicode if we support it */
+	if (g_fUnicodeSupport)
+	  SetClipboardData (CF_UNICODETEXT, NULL);
+
+	/* Always advertise regular text */
+	SetClipboardData (CF_TEXT, NULL);
+
+	/* Release the clipboard */
+	CloseClipboard ();
+      }
+      return 0;
     }
 
   /* Let Windows perform default processing for unhandled messages */