Simplify redisplay-x/separate_textual_runs

[Olivier Galibert]

On Sun, Apr 01, 2007 at 11:53:12PM +0900, Stephen J. Turnbull wrote:
> I think this is ready to go; I have no objection to applying it.
> 
> That said, there are two issues that I'd like insight into (no effect
> on your patch, as they apply to the original version too).  (They're
> flagged with #### in the patch below.)
> 
> 1.  I wonder if there might be efficiency implications to the
>     alignment of text_storage, since in many cases we'll be storing
>     shorts or integers into it.

Or correctness even.  I don't know is libXft is unaligned-resistant.


> 2.  I wonder what happens if `ccl_setup_program' fails?  Aidan, you're
>     the expert on CCL, any ideas?
> 
> Also, I'd like to suggest the patch below (to be applied *on top of*
> your patch).  It does the following:
> 
> 1.  Updates the big header comments.
> 2.  Add modest header comments to the Xft/no-Mule and no-Xft/Mule
>     versions.
> 3.  Cleans up a couple of inline comments.
> 4.  Removes some trailing whitespace.
> 
> More controversially,
> 
> 5.  Always initialize prev_charset to Qunbound, and nuke the comment
>     (I think it's unnecessary and potentially could be misleading if
>     (for example) Qnil came to represent the internal charset
>     (Unicode).
> 6.  Reorganize separate_textual_runs_mule and add comments to explain
>     what's going on.
> 
> What do you think?

I like it.

  OG.