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. The only thing I'm a bit nervous about is assuming that the maximum possible bit depth is 32; I've never heard of a higher-depth X visual, but that doesn't mean one doesn't exist. I also added a MIME type (image/x-xwindowdump) directive.
This fixes all of the MP3 files mentioned in the original bug report; if you have any others which exhibit the same problem, please link to them and I'll see what I can do to tighten up the match. If the patch needs to be in a different format (a debdiff, or a dpatch against current git), please let me know and I'll be happy to reformat it, or tailor it to address any other concerns. Adam Buchbinder
--- file/magic/Magdir/images 2009-01-29 16:01:53.000000000 -0500 +++ file/magic/Magdir/images 2009-02-14 22:43:58.000000000 -0500 @@ -307,11 +307,20 @@ # 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.
