Diffstat generation chokes on binaries (and others)

From the first day of preview-diff generation:

1 MalformedPatchHeader: Malformed patch header. No orig name 'Binary files lib/sltv.jar\\t1970-01-01 00:00:00 +0000 and lib/sltv.jar\\t2009-09-22 13:19:02 +0000 differ\\n'
Other: 1 Robots: 0 Local: 0
     OOPS-1363MPCJ3

1 MalformedHunkHeader: Malformed hunk header. Does not match format. '+DROP TABLE t1;\\n'
Other: 1 Robots: 0 Local: 0
     OOPS-1363MPCJ2

1 MalformedHunkHeader: Malformed hunk header. Does not match format. 'Binary files src/vagon/arm/media/css/blueprint/src/grid.png\\t2009-08-14 14:44:00 +0000 and src/vagon/arm/media/css/blueprint/src/grid.png\\t2009-09-08 20:08:06 +0000 differ\\n'
Other: 1 Robots: 0 Local: 0
     OOPS-1363MPCJ1