Hi Robert & Hironobu, On Tue, May 26, 2020 at 3:25 PM Hironobu Yamashita < h.y.acetaminophen@gmail.com> wrote:
Hi Robert,
Confirmed here; it seems that pdftex.web L.3779
@d auto_kern == explicit
is the culprit.
In your proposed MWE, when the function adjust_interword_glue() is called, the tail node is \kern1pt thus (type=kern_node) and (subtype=explicit). However, "@d auto_kern == explicit" is set, it falls through the following conditions.
else if (type(p) = kern_node) and (subtype(p) = auto_kern) and (save_tail <> null) then
When I change that line to
@d auto_kern == 3 {|acc_kern| + 1}
the problem is gone. I'm not sure whether there is some side effect.
I can confirm that Hironobu's analysis is correct. Thank you for your help. Regards, Thanh