overfull box in printed toc with @/

[Karl Berry]

Hi Gavin - with this input file:

\input texinfo
@contents
@chapter Test
@section Sec
@subsection 
foofoo@code{\DeclareRobustCommand@{@var{cmd}@}[@var{num}][@var{default}]@/@{@var{definition}@}
 }
@bye

I get an overfull box in the toc (texinfo.tex version 2023-09-12.17):

Overfull \hbox (65.62492pt too wide) in paragraph at lines 3--3
 [][][]@textrm foofoo@texttt \DeclareRobustCommand{@textttsl cmd@texttt }[@text
ttsl num@texttt ][@textttsl default@texttt ] |

The subsection title is painfully long, but it has to be, so I inserted
an @/ to allow a line break. The break happens but the line before the
break gets an overfull box, although no text is near the margin.
I'll attach the pdf I got (and .log, what the heck). --thanks, karl.

txilongsec.pdf
Description: Adobe PDF document

txilongsec.log
Description: Binary data