Re: XBM images sometimes inverted on Windows

[Neil Roberts]

On Sat, Dec 01, 2007 at 01:36:42PM +0000, Jason Rumney wrote:
> Does this result in a valid xbm image? There is no width and height
> specified, and the data is not in the textual format that an xbm is
> supposed to be in.

You are right it doesn't make a valid XBM image, but according to the
elisp manual this is a perfectly valid way of defining an image. The
width and height are specified in the property list instead:

38.16.2 XBM Images
------------------

...

`:data DATA'
     The value, DATA, specifies the contents of the image.  There are
     three formats you can use for DATA:

   ...

        * A string or a bool-vector containing the bits of the image
          (plus perhaps some extra bits at the end that will not be
          used).  It should contain at least WIDTH * `height' bits.  In
          this case, you must specify `:height' and `:width', both to
          indicate that the string contains just the bits rather than a
          whole XBM file, and to specify the size of the image.