patch for libimage on little-endian systems

[Jean-Francois Panisset <panisset@xxxxxxxxxxx>]

It seems that libimage (the library which handles I/O for SGI image 
files) is creating image with a header which is not byte-swapped on 
little-endian systems (the native byte order of SGI image files is 
big-endian). The support for correctly handling endianness is there, but 
it just forgets to byteswap the header before writing it out. I'm 
guessing that OpenInventor probably doesn't write images, just reads 
them (and that part works), but since the OpenInventor source tree is 
the only place I know where you can find this code (unless you've held 
on to your IRIX 5.3 IDO CDs with the 4DGifts stuff), I'd like to propose 
this patch to libimage/open.c for the sake of completeness:

		image->max = 0;
		isetname(image,"no name"); 
		image->wastebytes = 0;
!               if( (((unsigned short)*(unsigned char *)&image->imagic) |
!                   ((unsigned short)(*((unsigned char *)&image->imagic+1)) << 8))
!                   == IMAGIC ) {
!                   image->dorev = 1;
!                   cvtimage((int*)image);
!               } else
!                   image->dorev = 0;
		if (write(f,image,sizeof(IMAGE)) != sizeof(IMAGE)) {
		    free(image);
		    close(f);
		    i_errhdlr("iopen: error on write of image header\n");
		    return NULL;
		}
+               if( image->dorev )
+                   cvtimage((int*)image);
	} else {
		if (file)
		    f = open(file, rw? 2: 0);