Using a macro makes pdfetex quits and exits with bad status

Have tested again, with the problem still occurring with the development version.
The @ifset and @ifclear commands were removed.

@usubsec{16D,
Utilisation of Rapid Computations}

--------

texi2pdf 06a-amcoh.texi
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017/Debian) (preloaded format=pdfetex)
 restricted \write18 enabled.
entering extended mode
(./06a-amcoh.texi (/usr/share/texmf/tex/texinfo/texinfo.tex
Loading texinfo [version 2018-01-09.11]: pdf, fonts, markup, glyphs,
page headings, tables, conditionals, indexing, sectioning, toc, environments,
defuns, macros, cross references, insertions,
(/usr/share/texlive/texmf-dist/tex/generic/epsf/epsf.tex
This is `epsf.tex' v2.7.4 <14 February 2011>
) localization, formatting, and turning on texinfo input format.)
(../mastaba/ramasutra.texi) (./06c-amcoh-rfc.texi) [1{/var/lib/texmf/fonts/map/
pdftex/updmap/pdftex.map}] [-1] (6 @ Ameliorating Waveform Coherency)
Cross reference values unknown; you must run TeX again. [1] [2] [3] [4]
[5] [6] [7]
Overfull \hbox (40.24854pt too wide) detected at line 790
@smalli U[] @smallrm = []
[8] [9] [10] [11] [12]
Overfull \hbox (23.94524pt too wide) detected at line 1287
[] []
[13] [14] [15] [16] [17]
Underfull \hbox (badness 10000) in paragraph at lines 1719--1722
@textrm Equipped with the In-ner Prod-uct, the set of Fourier Ba-sis
[18] [19] [20] [21]
Runaway argument?
{
./06a-amcoh.texi:1958: Paragraph ended before @trim@ was complete.
<to be read again>
                   @par
<argument> ^^M
              Utilisation of Rapid Computations
@eatspaces ...@expandafter @trim@ @expandafter {#1
                                                   }
@value ...value {#1}@else @csname SET#1@endcsname
                                                  @fi
@writetocentry ...mp {@write @tocfile {@#1entry{#2
                                                  }{#3}{@lastnode }{@noexpan...

@sectionheading ...toctype @sectionlevel }{#1}{#4}
                                                  @donoderef {#3}@nobreak @v...
...
l.1958 Utilisation of Rapid Computations}

?
./06a-amcoh.texi:1958: Emergency stop.
<to be read again>
                   @par
<argument> ^^M
              Utilisation of Rapid Computations
@eatspaces ...@expandafter @trim@ @expandafter {#1
                                                   }
@value ...value {#1}@else @csname SET#1@endcsname
                                                  @fi
@writetocentry ...mp {@write @tocfile {@#1entry{#2
                                                  }{#3}{@lastnode }{@noexpan...

@sectionheading ...toctype @sectionlevel }{#1}{#4}
                                                  @donoderef {#3}@nobreak @v...
...
l.1958 Utilisation of Rapid Computations}

./06a-amcoh.texi:1958:  ==> Fatal error occurred, no output PDF file produced!
Transcript written on 06a-amcoh.log.
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017/Debian) (preloaded format=pdfetex)
 restricted \write18 enabled.
entering extended mode



Runaway argument?
{
./06a-amcoh.texi:1958: Paragraph ended before @trim@ was complete.
<to be read again>
                   @par
<argument> ^^M
              Utilisation of Rapid Computations
@eatspaces ...@expandafter @trim@ @expandafter {#1
                                                   }
@value ...value {#1}@else @csname SET#1@endcsname
                                                  @fi
@writetocentry ...mp {@write @tocfile {@#1entry{#2
                                                  }{#3}{@lastnode }{@noexpan...

@sectionheading ...toctype @sectionlevel }{#1}{#4}
                                                  @donoderef {#3}@nobreak @v...
...
l.1958 Utilisation of Rapid Computations}

?
./06a-amcoh.texi:1958: Emergency stop.
<to be read again>
                   @par
<argument> ^^M
              Utilisation of Rapid Computations
@eatspaces ...@expandafter @trim@ @expandafter {#1
                                                   }
@value ...value {#1}@else @csname SET#1@endcsname
                                                  @fi
@writetocentry ...mp {@write @tocfile {@#1entry{#2
                                                  }{#3}{@lastnode }{@noexpan...

@sectionheading ...toctype @sectionlevel }{#1}{#4}
                                                  @donoderef {#3}@nobreak @v...
...
l.1958 Utilisation of Rapid Computations}

./06a-amcoh.texi:1958:  ==> Fatal error occurred, no output PDF file produced!
Transcript written on 06a-amcoh.log.
/usr/local/bin/texi2dvi: pdfetex exited with bad status, quitting.



> Sent: Wednesday, June 23, 2021 at 8:01 AM
> From: "Gavin Smith" <[email protected]>
> To: "Christopher Dimech" <[email protected]>
> Cc: "help-texinfo gnu" <[email protected]>
> Subject: Re: Using a macro makes pdfetex quits and exits with bad status
>
> On Tue, Jun 22, 2021 at 6:53 PM Christopher Dimech <[email protected]> wrote:
> >
> > @macro usubsec {label, titl}
> >
> > @set lb \label\
> > @set tl \titl\
> > @ifclear usubsec-no-label
> >    @unnumberedsubsec @value{lb} @ @value{tl}
> > @end ifclear
> >
> > @ifset usubsec-no-label
> >   @unnumberedsubsec @value{tl}
> > @end ifset
> >
> > @end macro
> >
>
> This appears to work OK?
>
> Eli gave you good advice about putting the macro definition inside the
> conditionals rather than the other way around although I don't know if
> that is part of the problem here.
>
> I remember you had problems with newlines in macro arguments before
> but I thought we had fixed them. It wouldn't be surprising if there
> were still problems though.
>
> $ pdfetex test.texi
> This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017/Debian)
> (preloaded format=pdfetex)
>  restricted \write18 enabled.
> entering extended mode
> (./test.texi (./texinfo.tex Loading texinfo [version 2021-04-25.21]: pdf,
> fonts, glyphs, page headings, tables, conditionals, indexing, sectioning, toc,
> environments, defuns, macros, cross references, insertions, (./epsf.tex
> This is `epsf.tex' v2.7.4 <14 February 2011>
> ) localization, formatting, and turning on texinfo input format.) [1{/var/lib/t
> exmf/fonts/map/pdftex/updmap/pdftex.map}] )</usr/share/texlive/texmf-dist/fonts
> /type1/public/amsfonts/cm/cmbx12.pfb>
> Output written on test.pdf (1 page, 13595 bytes).
> Transcript written on test.log.
>