Re: Within `@code`, `@-` and `@/` are handled the same

[Werner LEMBERG]

> As can be seen in the attached output, there is no hyphen in the
> split word.  I consider this a bug, since there is zero reason for
> such a surprising (and undocumented) behaviour.
> 
> BTW, you get exactly the same output if you replace `@code` with `@t`
> – and *this* is definitely a bug :-)

Attached are two patches that fix both issues.  Note that the bug with
no hyphenation in `@t` is at least 20 years old...

I've also attached a sample document, together with an image of it.


    Werner

>From 414d2fd0d06383d6574163cdee564175a87a15c2 Mon Sep 17 00:00:00 2001
From: Werner Lemberg <wl@gnu.org>
Date: Thu, 15 Dec 2022 18:28:00 +0100
Subject: [PATCH 1/2] texinfo.tex: Make `\restorehyphenation` actually work.

After leaving a group, `\font` is usually a different font.  Without this
patch, the action of `\nohyphenation` was never reset in that case.
---
 doc/texinfo.tex | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/doc/texinfo.tex b/doc/texinfo.tex
index dbd5166014..a94e50c365 100644
--- a/doc/texinfo.tex
+++ b/doc/texinfo.tex
@@ -2821,8 +2821,12 @@ end
 % the end of a paragraph.  Restore normal hyphenation at the end of the
 % group within which \nohyphenation is presumably called.
 %
-\def\nohyphenation{\hyphenchar\font = -1  \aftergroup\restorehyphenation}
-\def\restorehyphenation{\hyphenchar\font = `- }
+\def\nohyphenation{%
+  \hyphenchar\font = -1
+  \xdef\nohyphenationfont{\the\font}%
+  \aftergroup\restorehyphenation \aftergroup\nohyphenationfont}
+\def\restorehyphenation#1{%
+  \hyphenchar#1 = `- }
 
 \newif\iffrenchspacing
 \frenchspacingfalse
-- 
2.39.0

>From e366314336a2c155bc64afcd82cd1b4dc77ff565 Mon Sep 17 00:00:00 2001
From: Werner Lemberg <wl@gnu.org>
Date: Thu, 15 Dec 2022 18:31:26 +0100
Subject: [PATCH 2/2] texinfo.tex: Make `@-` work in `@code`.

---
 doc/texinfo.tex | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/doc/texinfo.tex b/doc/texinfo.tex
index a94e50c365..d62dd02ee1 100644
--- a/doc/texinfo.tex
+++ b/doc/texinfo.tex
@@ -2899,9 +2899,12 @@ end
     % But `\ ' produces the large typewriter interword space.
     \def\ {{\spaceskip = 0pt{} }}%
     %
-    % Turn off hyphenation.
+    % Turn off pattern-based hyphenation ...
     \nohyphenation
     %
+    % ... but allow explicit insertion of hyphenation points.
+    \def\-{\discretionary{\normaldash}{}{}}%
+    %
     \plainfrenchspacing
     #1%
   }%
-- 
2.39.0

\input texinfo

@verb{|@t|}:

This is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word};
this is a @t{Long@-Long@-Word}.

This is a @t{Long-Long-Word};
this is a @t{Long-Long-Word};
this is a @t{Long-Long-Word};
this is a @t{Long-Long-Word};
this is a @t{Long-Long-Word};
this is a @t{Long-Long-Word};
this is a @t{Long-Long-Word};
this is a @t{Long-Long-Word}.

@sp 1
@verb{|@code|}:

This is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word}.

This is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word}.

@sp1
@verb{|@code & @allowcodebreaks false|}:

@allowcodebreaks false

This is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word};
this is a @code{Long@-Long@-Word}.

This is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word};
this is a @code{Long-Long-Word}.

@bye