[cl-typesetting-devel] apparent hyphenation-related bug and fix

[Chhi'med Kunzang]

I have encountered a weird bug, which is that when using some fonts at  
some sizes ("Times-Roman" at 12.0 for example), I get extra spacing  
inserted in the middle of words.  I haven't worked out exactly when  
this happens and why it sometimes doesn't, but it certainly does  
happen sometimes.  As it turns out the place where these spaces appear  
is where hyphens *would* appear if the line needed to be hyphenated.   
A quick tour through the code led me to believe that the placeholders  
for the hyphens were being left in and rendered as spaces.  However,  
the code is complex, and I don't pretend to completely understand it.

I came up with a simple solution which fixes my immediate problem, but  
I do not yet know if it may introduce new problems.  I am including  
the relevant information here so that someone more knowledgeable can  
verify this is the correct solution and can incorporate it (or a  
better solution) into the source at some point.

As far as I know, I am using the most recent version of the cl- 
typesetting.  My version is 0.8.

The solution was a simple conditional which prevents pushing the  
unneeded HYPHEN-BOX onto the current LINE-BOXES.

 From layout.lisp:

(defmethod fit-lines ((content text-content) dx dy &optional (v- 
align :top)(advance t))

<snip>

;	      ((<= next-x last-x) (push box line-boxes))
	      ((<= next-x last-x) (unless (typep box 'hyphen-box)
                                     (push box line-boxes)))

<snip>

       (return-lines))))

I hope that helps, if correct, and that if incorrect someone else  
might be able to suggest a better workaround.

Thanks,
Chhi'mèd