Author: Adam Buchbinder <adam.buchbinder@gmail.com>
Description:
 The XWD magic is too simple--it just matches a single big-endian long at the
 beginning of the file. This patch implements a few other checks
 (Closes: #511764).

diff -Naurp file.orig/magic/Magdir/images file/magic/Magdir/images
--- file.orig/magic/Magdir/images	2009-03-21 09:20:04.000000000 +0000
+++ file/magic/Magdir/images	2009-03-21 09:34:29.000000000 +0000
@@ -308,11 +308,20 @@
 #   As described in /usr/X11R6/include/X11/XWDFile.h
 #   used by the xwd program.
 #   Bradford Castalia, idaeim, 1/01
-4	belong	7			XWD X Window Dump image data
->100	string	>\0			\b, "%s"
->16	belong	x			\b, %dx
->20	belong	x			\b%dx
->12	belong	x			\b%d
+#   updated by Adam Buchbinder, 2/09
+# The following assumes version 7 of the format; the first long is the length
+# of the header, which is at least 25 4-byte longs, and the one at offset 8
+# is a constant which is always either 1 or 2. Offset 12 is the pixmap depth,
+# which is a maximum of 32.
+0	belong	>100
+>8	belong	<3
+>>12	belong	<33
+>>>4	belong	7			XWD X Window Dump image data
+!:mime	image/x-xwindowdump
+>>>>100	string	>\0			\b, "%s"
+>>>>16	belong	x			\b, %dx
+>>>>20	belong	x			\b%dx
+>>>>12	belong	x			\b%d
 
 # PDS - Planetary Data System
 #   These files use Parameter Value Language in the header section.