texinfo: Add '*line-width*' fluid to control line wrapping.

* module/texinfo/plain-text.scm (*line-width*): New variable.
(wrap*): Honor it.
* doc/ref/texinfo.texi (texinfo plain-text): Document it.
* test-suite/tests/texinfo.plain-text.test: New file.
* test-suite/Makefile.am (SCM_TESTS): Add it.

1 files changed, 7 insertions, 1 deletions

diff --git a/doc/ref/texinfo.texi b/doc/ref/texinfo.texi
index 5006fd427..64a866b23 100644
--- a/doc/ref/texinfo.texi
+++ b/doc/ref/texinfo.texi
@@ -1,6 +1,6 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Guile Reference Manual.
-@c Copyright (C) 2013 Free Software Foundation, Inc.
+@c Copyright (C) 2013, 2020 Free Software Foundation, Inc.
 @c See the file guile.texi for copying conditions.
 
 @c Note: Don't use "Texinfo" as the node name here because this leads to
@@ -452,6 +452,12 @@ Transform @var{tree} into plain text. Returns a string.
 
 @end defun
 
+@defvr {Scheme Variable} *line-width*
+This fluid (@pxref{Fluids and Dynamic States}) specifies the length of
+line for the purposes of line wrapping in the @code{stexi->plain-text}
+conversion.
+@end defvr
+
 @node texinfo serialize
 @subsection (texinfo serialize)
 @subsubsection Overview