On Thursday, March 5th, 2026 at 2:44 PM, Udi Fogiel wrote:

I attached a fix.

Note that if the paragraph is starting inside of a group then the fix won't work, as no_local_dirs_par is set locally =============== run \linedirection=1 run \linedirection=0 run % the next paragraph is starting inside a group {run} {\linedirection=1 run} run \linedirection=1 run \linedirection=0 run Some more\hfill\break text \bye ================== So the patch does not fix everything, but it certainly improves the situation. Udi

On Thu, 5 Mar 2026 at 14:52, Udi Fogiel wrote:

On Thursday, March 5th, 2026 at 3:10 PM, Udi Fogiel wrote:

...

On Thursday, March 5th, 2026 at 2:44 PM, Udi Fogiel < udi.fogiel@proton.me> wrote:

...

I attached a fix.

Note that if the paragraph is starting inside of a group then the fix won't work, as no_local_dirs_par is set locally

=============== run \linedirection=1 run \linedirection=0 run

% the next paragraph is starting inside a group {run} {\linedirection=1 run} run \linedirection=1 run \linedirection=0 run Some more\hfill\break text

\bye ==================

So the patch does not fix everything, but it certainly improves the situation.

Another solution which works even in this case is to always inject dir nodes from the stack, even if the direction is the same as pardirection. See the attached diff.

Ok, I will check them later. -- luigi

On Wednesday, April 1st, 2026 at 7:13 PM, luigi scarso wrote:

Sorry for the delay, I had already seen it but then I was busy with other things related to Luatex. Re-checking it now.

Thanks luigi. After giving it some more thought, the first patch does not fix everything (as mentioned previously), and the second one is probably not backwards compatible as it creates direction nodes is situations where previously weren't any (and this for example can affect vertical spacing around display if \mathemptydisplamode is not set). There is a simple ad hoc solution, which can also be done from Lua: \directlua{ callback.register("pre_linebreak_filter", function(head) local stack = 0 for n, sb in node.traverse_id(node.id('dir'),head) do stack = stack + 1-2*sb if stack == -1 then head = node.remove(head,n) return head end end return head end) } Something similar can be done from C before the callback kicks in (so that callback order won't matter and the fix will be made in all formats). But maybe after looking into it you found a better solution (hopefully). Udi