Re: Bug in dumpdef's documentation

On Tue, Oct 26, 2021 at 07:45:06PM +0200, Patrice Dumas wrote:
> > @c @tabchar{}
> > @c ----------
> > @c The testsuite expects literal tab output in some examples, but
> > @c literal tabs in texinfo lead to formatting issues.
> > @macro tabchar
> > @       @c
> > @end macro
> > 
> > So maybe the problem is that the macro expansion is leaving a bare @c
> > which then eats the rest of the line when using the macro within
> > @example.
> 
> It is indeed what happens, the expansion of the texinfo conserves the
> @c. (macro expansion can be tested with the -M option).  So `Hello world.'
> and <define> disappear:
> 
...
> One possibility is to add an end of line in the macro definition, which
> should work for texi2any:
> 
> @c @tabchar{}
> @c ----------
> @c The testsuite expects literal tab output in some examples, but
> @c literal tabs in texinfo lead to formatting issues.
> @macro tabchar
> @	@c
> 
> @end macro
> 
> However, this needs to be tested with texi2pdf, as texi2pdf may need
> something else.

Yay, that did it!  I tested info, html, and pdf output, and all of
them rendered the way I wanted once I added the newline (my worry was
an unexpected mid-line break appearing in the rendered example, but
thankfully that did not happen); and the testsuite still passed (it
extracts @examples from the manual, and uses sed to convert @tabchar{}
into a literal tab to match what m4 actually produces).

I'll commit the fix into m4.git shortly, although the online manual
won't be updated until the 1.4.20 release.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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