[gtk+/gtk-2-24-quartz] win32: fix pasting screenshots taken with PrintScreen or Alt+PrintScreen

[John Ralls <jralls src gnome org>]

commit bcf24879342fa0a3dbed342d307db5808eb388e0
Author: Dieter Verfaillie <dieterv optionexplicit be>
Date:   Fri Nov 4 09:44:35 2011 +0100

    win32: fix pasting screenshots taken with PrintScreen or Alt+PrintScreen
    
    These are found on the clipboard in the biCompression == BI_BITFIELDS &&
    biBitCount >= 16 format. In this case the BITMAPINFOHEADER is followed
    by three DWORD specifying the masks of the red green and blue components,
    but bfOffBits was not being adjusted accordingly.
    
    Based on Massimo's comment on bug 631384 and verified on
    http://msdn.microsoft.com/en-us/library/dd183386%28v=VS.85%29.aspx
    
    https://bugzilla.gnome.org/show_bug.cgi?id=631384

 gdk/win32/gdkselection-win32.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/gdk/win32/gdkselection-win32.c b/gdk/win32/gdkselection-win32.c
index 3fb46b9..86f42b2 100644
--- a/gdk/win32/gdkselection-win32.c
+++ b/gdk/win32/gdkselection-win32.c
@@ -718,6 +718,17 @@ gdk_selection_convert (GdkWindow *requestor,
 				       bi->biSize +
 				       bi->biClrUsed * sizeof (RGBQUAD));
 
+		      if (bi->biCompression == BI_BITFIELDS && bi->biBitCount >= 16)
+		        {
+                          /* Screenshots taken with PrintScreen or
+                           * Alt + PrintScreen are found on the clipboard in
+                           * this format. In this case the BITMAPINFOHEADER is
+                           * followed by three DWORD specifying the masks of the
+                           * red green and blue components, so adjust the offset
+                           * accordingly. */
+		          bf->bfOffBits += (3 * sizeof (DWORD));
+		        }
+
 		      memcpy ((char *) data + sizeof (BITMAPFILEHEADER),
 			      bi,
 			      data_length);