eplain[59] trunk: doublecolumns + marks bug reported by ldf

[commits+karl at tug.org]

Revision: 59
          http://tug.org/svn/eplain?view=revision&revision=59
Author:   karl
Date:     2022-10-06 00:29:56 +0200 (Thu, 06 Oct 2022)
Log Message:
-----------
doublecolumns + marks bug reported by ldf

Modified Paths:
--------------
    trunk/ChangeLog
    trunk/doc/Makefile
    trunk/doc/userdef.texi
    trunk/xeplain.tex

Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog	2022-10-03 15:04:43 UTC (rev 58)
+++ trunk/ChangeLog	2022-10-05 22:29:56 UTC (rev 59)
@@ -1,3 +1,13 @@
+2022-10-05  Karl Berry  <karl at freefriends.org>
+
+	* xeplain.tex: document bug in double-columns that marks are not
+	always preserved. See threads:
+	https://tug.org/pipermail/tex-eplain/2021/001001.html
+	https://tug.org/pipermail/tex-eplain/2022/001049.html
+	* doc/userdef.texi: mention mark bug.
+
+	* doc/Makefile (MAKEINFO_HTML):	https for TOP_NODE_UP_URL.
+
 2022-10-03  Karl Berry  <karl at freefriends.org>
 
 	* Makefile (fetch, fetch1): new targets.

Modified: trunk/doc/Makefile
===================================================================
--- trunk/doc/Makefile	2022-10-03 15:04:43 UTC (rev 58)
+++ trunk/doc/Makefile	2022-10-05 22:29:56 UTC (rev 59)
@@ -4,7 +4,7 @@
 MAKEINFO        = makeinfo
 MAKEINFO_FLAGS  = 
 MAKEINFO_HTML   = $(MAKEINFO_FLAGS) --html \
-                 -c TOP_NODE_UP_URL=http://tug.org/texinfohtml/
+                 -c TOP_NODE_UP_URL=https://tug.org/texinfohtml/
 
 # for quieter TeX
 TEXFOT          = texfot
@@ -113,3 +113,6 @@
 maintainer-clean: distclean
 	rm -f $(JPG_DEMOS)
 	rm -f ../INSTALL eplain.info eplain.pdf eplain.html eplain.man1.pdf
+
+svr:
+	svn revert eplain.info eplain.pdf

Modified: trunk/doc/userdef.texi
===================================================================
--- trunk/doc/userdef.texi	2022-10-03 15:04:43 UTC (rev 58)
+++ trunk/doc/userdef.texi	2022-10-05 22:29:56 UTC (rev 59)
@@ -1865,7 +1865,7 @@
 now we'll describe the exceptions.
 
 The following characters are reset to their usual meanings because
-they are not useful verbatim:  multiple consequent spaces are
+they are not useful verbatim:  multiple consecutive spaces are
 converted into a single space; ASCII tab characters are
 treated as spaces; ASCII return is treated as end-of-line
 (this means, among other things, that long terms can be broken across
@@ -2002,8 +2002,8 @@
 @cindex index fonts
 @findex indexfonts
 @cindex double columns in indexes
-Eplain calls @code{\indexfonts}, sets @code{\parindent = 0pt}, and does
- at code{\doublecolumns} (@pxref{Multiple columns}) at the
+Eplain calls @code{\indexfonts}, sets @code{\parindent = 0pt}, and
+does @code{\doublecolumns} (@pxref{Multiple columns}) at the
 @code{\begin@{theindex@}}. @code{\indexfonts} does nothing by default;
 it's just there for you to override. (Indexes are usually typeset in
 smaller type than the main text.)
@@ -2494,7 +2494,7 @@
 multicolumns, Eplain multiplies @code{\vsize} itself by the number of
 columns).  In most circumstances, a column break will be forced after
 this space (during the column splitting operation when the whole page
-is output).  Bugs are easily possible, unfortunately.
+is output).
 
 @findex gutter
 The columns are separated by the value of the dimen parameter
@@ -2509,6 +2509,15 @@
 \def\gutterbox@{\vbox to \dimen0@{\vfil\hbox@{\vrule height\dimen0@}\vfil@}@}%
 @end example
 
+There are known bugs in the multiple-column code such that
+ at code{\topmark} and possibly other marks can have an incorrect value
+on the last page of multiple-column material when using
+ at code{\singlecolumn} to balance the columns.  Unfortunately this is
+quite difficult to fix, and at present (volunteers welcome), it's
+going to remain.  A suboptimal workaround is to insert
+ at code{\columnfill} at the appropriate place.
+ at c (See xeplain.tex for more about this bug.)
+
 @noindent The dimension counter
 @code{\dimen0}
 contains the height of the column.

Modified: trunk/xeplain.tex
===================================================================
--- trunk/xeplain.tex	2022-10-03 15:04:43 UTC (rev 58)
+++ trunk/xeplain.tex	2022-10-05 22:29:56 UTC (rev 59)
@@ -3443,6 +3443,10 @@
 % The basic approach is that of Appendix E of the TeXbook, p.417.
 % David Guichard made significant improvements to my original implementation.
 %
+% A fundamental bug is that marks are not always preserved. See:
+%   https://tug.org/pipermail/tex-eplain/2021/001001.html
+%   https://tug.org/pipermail/tex-eplain/2022/001049.html
+%
 % The glue here (the default is intended to be one linespace) is inserted
 % before double columns start, and after they end.
 %