TODO

   1 ************************************************************************
   2 * Official mandoc TODO.
   3 * $Id: TODO,v 1.320 2021/10/01 08:58:37 schwarze Exp $
   4 ************************************************************************
   5
   6 Many issues are annotated for difficulty as follows:
   7
   8  - loc = locality of the issue
   9     *    single file issue, affects file only, or very few
  10     **   single module issue, affects several files of one module
  11     ***  cross-module issue, significantly impacts multiple modules
  12          and may require substantial changes to internal interfaces
  13  - exist = difficulty of the existing code in this area
  14     *    affected code is straightforward and easy to read and change
  15     **   affected code is somewhat complex, but once you understand
  16          the design, not particularly difficult to understand
  17     ***  affected code uses a special, exceptionally tricky design
  18  - algo = difficulty of the new algorithm to be written
  19     *    the required logic and code is straightforward
  20     **   the required logic is somewhat complex and needs a careful design
  21     ***  the required logic is exceptionally tricky,
  22          maybe an approach to solve that is not even known yet
  23  - size = the amount of code to be written or changed
  24     *    a small number of lines (at most 100, usually much less)
  25     **   a considerable amount of code (several dozen to a few hundred)
  26     ***  a large amount of code (many hundreds, maybe thousands)
  27  - imp = importance of the issue
  28     *    mostly for completeness
  29     **   would be nice to have
  30     ***  issue causes considerable inconvenience
  31
  32 Obviously, as the issues have not been solved yet, these annotations
  33 are mere guesses, and some may be wrong.
  34
  35 ************************************************************************
  36 * assertion failures
  37 ************************************************************************
  38
  39 - .if n .ce in the middle of .TS data
  40   afl case f1/id:000103,sig:06,src:009024+009105,op:splice,rep:2 (jes@)
  41   While roff_parseln() prevents .ce and similar requests in the middle
  42   of a tbl, the guard is no longer effective when the .ce is wrapped
  43   in a roff block, for example a conditional.  The resulting assertion
  44   has never been seen in any real-world manual page.
  45   This is too dangerous to fix before release because it requires
  46   reorganizing the very delicate internals of roff_parseln(),
  47   which risks causing more severe bugs.
  48   loc * exist *** algo *** size * imp *
  49
  50
  51 ************************************************************************
  52 * bugs: invalid output
  53 ************************************************************************
  54
  55 - wrong number of layout columns in tbl(7) code generated by -T man
  56   https://savannah.gnu.org/bugs/?57720
  57   The reason likely is that tbl(7) does not support the -Bl -column
  58   feature of not explicitly specifying the last table column.
  59   loc **  exist *  algo **  size *  imp ***
  60
  61 - eqn(7) delimiters cause conditional lines to misbehave
  62   nabijaczleweli 8 Sep 2021 15:24:48 +0200
  63   loc *  exist ***  algo ***  size *  imp *
  64
  65 - roff.c, roff_expand() should not remove blanks before comments
  66   to Oliver Corff, Sep 7, 2021
  67   loc *  exist *  algo *  size *  imp *
  68   but watch out for regressions in the high-level parsers
  69   maybe it should not even remove comments? - consider T{\"
  70
  71 - tag.c, tag_put() should not put ASCII_HYPH into the tag file,
  72   which happens when the tag contains "-" on the input side
  73   weerd@ 28 Sep 2021 12:44:07 +0200
  74   loc *  exist *  algo *  size *  imp ***
  75
  76
  77 ************************************************************************
  78 * missing features
  79 ************************************************************************
  80
  81 --- missing roff features ----------------------------------------------
  82
  83 - .ad (adjust margins)
  84   .ad l -- adjust left margin only (flush left)
  85   .ad r -- adjust right margin only (flush right)
  86   .ad c -- center text on line
  87   .ad b -- adjust both margins (alias: .ad n)
  88   .na   -- temporarily disable adjustment without changing the mode
  89   .ad   -- re-enable adjustment without changing the mode
  90   Adjustment mode is ignored while in no-fill mode (.nf).
  91   loc ***  exist ***  algo **  size **  imp **  (parser reorg would help)
  92
  93 - .fc (field control)
  94   found by naddy@ in xloadimage(1)
  95   loc **  exist ***  algo *  size *  imp *
  96
  97 - .ns (no-space mode) occurs in xine-config(1)
  98   when implementing this, also let .TH set it
  99   reported by brad@  Sat, 15 Jan 2011 15:45:23 -0500
 100   loc ***  exist ***  algo ***  size **  imp *
 101
 102 - \w'' improve width measurements
 103   would not be very useful without an expression parser, see below
 104   needed for Tcl_NewStringObj(3) via wiz@  Wed, 5 Mar 2014 22:27:43 +0100
 105   loc **  exist ***  algo ***  size *  imp ***
 106
 107 - .als only works for macros in mandoc, not for user-defined strings.
 108   Also, the "val" field in struct roffkv would have to be replaced
 109   with a pointer to a reference-counted wrapper, and an alias
 110   would have to point to the same wrapper as the original.
 111   .als to undefined does nothing; the alias is not created.
 112   .rm'ing the original leaves the alias to point to the old value.
 113   .de .als .de changes both, but
 114   .de .als .rm .de only changes the new value, not the alias.
 115   Found in groffer(1) version 1.19
 116   Jan Stary 20 Apr 2019 20:16:54 +0200
 117   loc *  exist **  algo **  size **  imp *
 118
 119 - roff string condition comparisons fail when vars contain quotes:
 120   .ds s '
 121   .if '\*s'' \&...
 122   hard to fix because of the basic architecture (string replacement
 123   happens before roff(7) syntax parsing)
 124   Found in groffer(1) version 1.19
 125   Jan Stary 20 Apr 2019 20:16:54 +0200
 126   loc *  exist ***  algo ***  size **  imp *
 127
 128 - mandoc replaces all ASCII control characters except tab and line feed
 129   with '?' during input.  It would be better to replace them with
 130   Unicode escapes in preconv_encode() or somewhere in the vicinity,
 131   such that the already existing better replacement strings show
 132   up in the output.  Emulating groff is not desirable: groff replaces
 133   0x00, 0x0b, and 0x0d to 0x1f with the empty string (bad because
 134   that's easy to overlook for the document author), 0x01 with '.'
 135   (very confusing), and passes through 0x02 to 0x08, 0x0c, and 0x7f
 136   raw (bad because that is insecure output).  Remember that 0x07 may
 137   need special handling because it is sometimes used for certain
 138   delimiters, so it may need handling *after* roff.c rather than before.
 139   reminded by John Gardner 16 Jun 2020 14:26:28 +1000
 140   Actually, more ASCII control characters than just 0x07 may need
 141   later handling because they can for example be used in macro names.
 142   So they may need handling after roff(7) processing.
 143   pointed out by John Gardner 23 Jun 2020 18:28:08 +1000
 144   more info from John Gardner 29 Jun 2020 19:54:04 +1000
 145   loc **  exist **  algo **  size **  imp *
 146
 147 - many missing features used in old groff_char(7),
 148   some can possibly be supported
 149   kamil at netbsd 12 Nov 2020 17:27:09 +0100 + reply
 150
 151 - \s with arbitrary arg delimiters as already supported for other escapes
 152   found following jmc@'s mail 28 Apr 2021 18:31:41 +0100
 153   loc *  exist *  algo *  size *  imp *
 154
 155 --- missing mdoc features ----------------------------------------------
 156
 157 - .Sh and .Ss should be parsed and partially callable, see groff_mdoc(7)
 158   reed at reedmedia dot net Sat, 21 Dec 2019 17:13:07 -0600
 159   loc **  exist **  algo **  size **  imp *
 160
 161 - .Bl -column .Xo support is missing
 162   ultimate goal:
 163   restore .Xr and .Dv to
 164   lib/libc/compat-43/sigvec.3
 165   lib/libc/gen/signal.3
 166   lib/libc/sys/sigaction.2
 167   loc *  exist ***  algo ***  size *  imp **
 168
 169 - edge case: decide how to deal with blk_full bad nesting, e.g.
 170   .Sh .Nm .Bk .Nm .Ek .Sh found by jmc@ in ssh-keygen(1)
 171   from jmc@  Wed, 14 Jul 2010 18:10:32 +0100
 172   loc *  exist ***  algo ***  size **  imp **
 173
 174 - .Bd -filled should not be the same as .Bd -ragged, but align both
 175   the left and right margin.  In groff, it is implemented in terms
 176   of .ad b, which we don't have either.  Found in cksum(1).
 177   loc ***  exist ***  algo **  size **  imp **  (parser reorg would help)
 178
 179 - implement blank `Bl -column', such as
 180   .Bl -column
 181   .It foo Ta bar
 182   .El
 183   loc *  exist ***  algo ***  size *  imp *
 184
 185 - explicitly disallow nested `Bl -column', which would clobber internal
 186   flags defined for struct mdoc_macro
 187   loc *  exist *  algo *  size *  imp **
 188
 189 - In .Bl -column .It, the end of the line probably has to be regarded
 190   as an implicit .Ta, if there could be one, see the following mildly
 191   ugly code from login.conf(5):
 192     .Bl -column minpasswordlen program xetcxmotd
 193     .It path Ta path Ta value of Dv _PATH_DEFPATH
 194     .br
 195     Default search path.
 196   reported by Michal Mazurek <akfaew at jasminek dot net>
 197   via jmc@ Thu, 7 Apr 2011 16:00:53 +0059
 198   loc *  exist ***  algo **  size *  imp **
 199
 200 - inside `.Bl -column' phrases, punctuation is handled like normal
 201   text, e.g. `.Bl -column .It Fl x . Ta ...' should give "-x -."
 202
 203 - inside `.Bl -column' phrases, TERMP_IGNDELIM handling by `Pf'
 204   is not safe, e.g. `.Bl -column .It Pf a b .' gives "ab."
 205   but should give "ab ."
 206
 207 - prohibit `Nm' from having non-text HEAD children
 208   (e.g., NetBSD mDNSShared/dns-sd.1)
 209   (mdoc_html.c and mdoc_term.c `Nm' handlers can be slightly simplified)
 210
 211 - support translated section names
 212   e.g. x11/scrotwm scrotwm_es.1:21:2: error: NAME section must be first
 213   that one uses NOMBRE because it is spanish...
 214   deraadt tends to think that section-dependent macro behaviour
 215   is a bad idea in the first place, so this may be irrelevant
 216   loc **  exist **  algo **  size *  imp **
 217
 218 - When there is free text in the SYNOPSIS and that free text contains
 219   the .Nm macro, groff somehow understands to treat the .Nm as an in-line
 220   macro, while mandoc treats it as a block macro and breaks the line.
 221   No idea how the logic for distinguishing in-line and block instances
 222   should be, needs investigation.
 223   uqs@  Thu, 2 Jun 2011 11:03:51 +0200
 224   uqs@  Thu, 2 Jun 2011 11:33:35 +0200
 225   loc *  exist **  algo ***  size *  imp **
 226
 227 --- missing man features -----------------------------------------------
 228
 229 - MANWIDTH
 230   Markus Waldeck <waldeck at gmx dot de> 9 Jun 2015 05:49:56 +0200
 231   Laura Morales <lauretas at mail dot com> 26 Apr 2018 08:15:55 +0200
 232   Kamil Rytarowski <kamil at netbsd> 13 Nov 2020 00:19:36 +0100
 233   patch from Kamil 13 Nov 2020 22:37:07 +0100
 234   loc *  exist *  algo *  size *  imp *
 235
 236 - groff_www(7) .MTO and .URL
 237   These macros were used by the GNU grep(1) man page.
 238   The groff_www(7) manual page itself uses them, too.
 239   We should probably *not* add them to mandoc.
 240   Just mentioning this here to keep track of the abuse.
 241   Laura Morales <lauretas at mail dot com> 20 Apr 2018 07:33:02 +0200
 242   loc **  exist *  algo *  size **  imp *
 243
 244 --- missing tbl features -----------------------------------------------
 245
 246 - vertical centering in cells vertically spanned with ^
 247   pali dot rohar at gmail dot com 16 Jul 2018 13:03:35 +0200
 248   loc *  exist ***  algo ***  size **  imp *
 249
 250 - support mdoc(7) and man(7) macros inside tbl(7) code;
 251   probably requires the parser reorg and letting tbl(7)
 252   use roff_node such that macro sets can mix;
 253   informed by bapt@ that FreeBSD needs this: 3 Jan 2015 23:32:23 +0100
 254   loc ***  exist **  algo ***  size **  imp ***
 255
 256 - look at the POSIX manuals in the books/man-pages-posix port,
 257   they use some unsupported tbl(7) features, mostly macros in tbl(7).
 258   loc *  exist **  algo **  size **  imp ***
 259
 260 - look what Joerg Schilling manual pages use
 261   Thu, 19 Mar 2015 18:31:48 +0100
 262
 263 --- missing eqn features -----------------------------------------------
 264
 265 - In a matrix, break the output line after each matrix line.
 266   Found in the discussion at CDBUG 2015.  Suggested by Avi Weinstock.
 267   This may not be the ideal solution after all: eqn(7) matrices
 268   are lists of columns, so Avi's proposal would show each *column*
 269   on its own *line*, which is likely to cause confusion.
 270   A better solution, but much harder to implement, would be to
 271   actually show the coordinates of column vectors on different
 272   terminal output lines, using the clumnated output facilities
 273   developed for .Bl -tag, .Bl -column, and also used for tbl(7).
 274   loc *  exist *  algo **  size **  imp **
 275
 276 - The "size" keyword is parsed, but ignored by the formatter.
 277   loc *  exist *  algo *  size *  imp *
 278
 279 - The spacing characters `~', `^', and tab are currently ignored,
 280   see User's Guide (Second Edition) page 2 section 4.
 281   loc *  exist *  algo **  size *  imp **
 282
 283 - Mark and lineup are parsed and ignored,
 284   see User's Guide (Second Edition) page 5 section 15.
 285   loc **  exist **  algo **  size **  imp **
 286
 287 - GNU eqn converts some operators to special characters, for example,
 288   input HYPHEN-MINUS becomes output \(mi, unless it is part of a
 289   quoted word.  mandoc(1) only does this when the operator is
 290   surrounded by blanks, not when it is part of an unquoted word.
 291   Also, check whether there are more such cases (e.g., +?).
 292   reported by bentley@  20 Jun 2017 02:04:29 -0600
 293   loc *  exist **  algo **  size *  imp *
 294
 295 - Primes, opprime, and '
 296   bentley@  Thu, 13 Jul 2017 23:14:20 -0600
 297
 298 --- missing misc features ----------------------------------------------
 299
 300 - conisder whether man(1) fallback code in main.c/fs_*() can find files
 301   like man3c/fopen.3c (illumos, Solaris) and man3p/fopen.3p (POSIX)
 302   discussed with Robert Mustacchi 21 Sep 2021 10:39:40 -0700
 303   loc *  exist *  algo **  size *  imp **
 304
 305 - let makewhatis(8) follow symbolic links to dirs below READ_ALLOWED_PATH
 306   this may be feasible using fts_set(FTS_FOLLOW)
 307   mail to sternenseemann 19 Aug 2021 19:11:50 +0200
 308   loc *  exist **  algo **  size *  imp **
 309
 310 - tag.c, tag_put() and callers like man_validate.c, check_tag()
 311   should not mistake "\-" as a word-ending escape sequence but
 312   instead translate it to plain "-" in the tag name
 313   weerd@ 28 Sep 2021 12:44:07 +0200
 314   loc **  exist *  algo *  size *  imp ***
 315
 316 - -T man does not handle eqn(7) and tbl(7)
 317   Stephen Gregoratto 16 Feb 2020 01:28:07 +1100
 318   also https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901636
 319   loc **  exist **  algo **  size ***  imp **
 320
 321 - man -ks 1,8 route; kn@ Jul 13, 2018 orally
 322
 323 - italic correction (\/) in PostScript mode
 324   Werner LEMBERG on groff at gnu dot org  Sun, 10 Nov 2013 12:47:46
 325   loc **  exist **  algo *  size *  imp *
 326
 327 - change the default PAGER to more -Es and use the pager
 328   even for apropos title line output; req by bapt@
 329   loc *  exist *  algo *  size *  imp ***
 330
 331 - clean up escape sequence handling, creating three classes:
 332   (1) fully implemented, or parsed and ignored without loss of content
 333   (2) unimplemented, potentially causing loss of content
 334       or serious mangling of formatting (e.g. \n) -> ERROR
 335       see textproc/mgdiff(1) for nice examples
 336   (3) undefined, just output the character -> perhaps WARNING
 337   loc ***  exist **  algo **  size **  imp *** (parser reorg helps)
 338
 339 - kettenis wants base roff, ms, and me  Fri, 1 Jan 2010 22:13:15 +0100 (CET)
 340   loc **  exist **  algo **  size ***  imp *
 341
 342 --- compatibility checks -----------------------------------------------
 343
 344 - is .Bk implemented correctly in modern groff?
 345   sobrado@  Tue, 19 Apr 2011 22:12:55 +0200
 346
 347 - compare output to Heirloom roff, Solaris roff, and
 348   http://repo.or.cz/w/neatroff.git  http://litcave.rudi.ir/
 349
 350 - look at AT&T DWB http://www2.research.att.com/sw/download
 351   Carsten Kunze <carsten dot kunze at arcor dot de> has patches
 352   Mon, 4 Aug 2014 17:01:28 +0200
 353   ported version: https://github.com/n-t-roff/DWB3.3
 354   Carsten Kunze  Wed, 22 Apr 2015 11:21:43 +0200
 355
 356 - look at pages generated from reStructeredText, e.g. devel/mercurial hg(1)
 357   These are a weird mixture of man(7) and custom autogenerated low-level
 358   roff stuff.  Figure out to what extent we can cope.
 359   For details, see http://docutils.sourceforge.net/rst.html
 360   noted by stsp@  Sat, 24 Apr 2010 09:17:55 +0200
 361   reminded by nicm@  Mon, 3 May 2010 09:52:41 +0100
 362
 363 - look at pages generated from ronn(1) github.com/rtomayko/ronn
 364   (based on markdown)
 365
 366 - look at pages generated from Texinfo source by yat2m, e.g. security/gnupg
 367   First impression is not that bad.
 368
 369 - look at pages generated by pandoc; see
 370   https://github.com/jgm/pandoc/blob/master/src/Text/Pandoc/Writers/Man.hs
 371   porting planned by kili@  Thu, 19 Jun 2014 19:46:28 +0200
 372
 373 - check compatibility with Plan9:
 374   http://swtch.com/usr/local/plan9/tmac/tmac.an
 375   http://swtch.com/plan9port/man/man7/man.html
 376   "Anthony J. Bentley" <anthonyjbentley@gmail.com> 28 Dec 2010 21:58:40 -0700
 377
 378 - check compatibility with COHERENT troff:
 379   http://www.nesssoftware.com/home/mwc/source.php
 380
 381 - check compatibility with the man(7) formatter
 382   https://raw.githubusercontent.com/rofl0r/hardcore-utils/master/man.c
 383
 384 - check compatibility with
 385   http://ikiwiki.info/plugins/contrib/mandoc/
 386   https://github.com/schmonz/ikiwiki/compare/mandoc
 387   Amitai Schlair  Mon, 19 May 2014 14:05:53 -0400
 388
 389 - check compatibility with
 390   https://git.sr.ht/~sircmpwn/scdoc
 391
 392 - check features of the Slackware man.conf(5) format
 393   Carsten Kunze  Wed, 11 Mar 2015 17:57:24 +0100
 394
 395 - look at http://www.snake.net/software/troffcvt/  (troff to HTML)
 396   mentioned by Oliver Corff  22 Jan 2021 01:36:49 +0100
 397
 398
 399 ************************************************************************
 400 * formatting issues: ugly output
 401 ************************************************************************
 402
 403 - revisit empty in-line macros
 404   look at the difference between "Em x Em ." and "Sq x Em ."
 405   Carsten Kunze  Fri, 12 Dec 2014 00:15:41 +0100
 406   loc *** exist *** algo *** size * imp **
 407
 408 - a column list with blank `Ta' cells triggers a spurious
 409   start-with-whitespace printing of a newline
 410
 411 - In .Bl -column, .It a<tab>"b<tab>c"
 412   shows the quotes in groff, but not in mandoc
 413   loc * exist *** algo ** size * imp **
 414
 415 - In .Bl -column,
 416   .It Em Authentication<tab>Key Length
 417   ought to render "Key Length" with emphasis, too,
 418   see OpenBSD iked.conf(5).
 419   reported again Nicolas Joly via wiz@ Wed, 12 Oct 2011 00:20:00 +0200
 420   loc *  exist ***  algo ***  size **  imp ***
 421
 422 - empty phrases in .Bl column produce too few blanks
 423   try e.g. .Bl -column It Ta Ta
 424   reported by millert Fri, 02 Apr 2010 16:13:46 -0400
 425   loc *  exist ***  algo ***  size *  imp **
 426
 427 - .%T can have trailing punctuation.  Currently, it puts the trailing
 428   punctuation into a trailing MDOC_TEXT element inside its own scope.
 429   That element should rather be outside its scope, such that the
 430   punctuation does not get underlines.  This is not trivial to
 431   implement because .%T then needs some features of in_line_eoln() -
 432   slurp all arguments into one single text element - and one feature
 433   of in_line() - put trailing punctuation out of scope.
 434   Found in mount_nfs(8) and exports(5), search for "Appendix".
 435   loc **  exist **  algo ***  size *  imp **
 436
 437 - Trailing punctuation after .%T triggers EOS spacing, at least
 438   outside .Rs (eek!).  Simply setting ARGSFL_DELIM for .%T is not
 439   the right solution, it sends mandoc into an endless loop.
 440   reported by Nicolas Joly  Sat, 17 Nov 2012 11:49:54 +0100
 441   loc *  exist **  algo **  size *  imp **
 442
 443 - global variables in the SYNOPSIS of section 3 pages
 444   .Vt vs .Vt/.Va vs .Ft/.Va vs .Ft/.Fa ...
 445   from kristaps@  Tue, 08 Jun 2010 11:13:32 +0200
 446
 447 - implicit whitespace around inline equations
 448   example code:  where '$times$' denotes matrix multiplication
 449   must not have an HTML line break, nor a blank, before <math>
 450   partial solution: html.c {"math", HTML_NLINSIDE | HTML_INDENT},
 451   bentley@  Thu, 13 Jul 2017 19:00:59 -0600
 452
 453 - in enclosures, mandoc sometimes fancies a bogus end of sentence
 454   reminded by jmc@  Thu, 23 Sep 2010 18:13:39 +0059
 455   loc *  exist **  algo ***  size *  imp ***
 456
 457 - a line starting with "\fB something" counts as starting with whitespace
 458   and triggers a line break; found in audio/normalize-mp3(1)
 459   This will become easier once escape sequences are represented
 460   by syntax tree nodes.
 461   loc **  exist *  algo **  size *  imp **
 462
 463 - formatting /usr/local/man/man1/latex2man.1 with groff and mandoc
 464   reveals lots of bugs both in groff and mandoc...
 465   reported by bentley@  Wed, 22 May 2013 23:49:30 -0600
 466
 467 --- PostScript and PDF issues ------------------------------------------
 468
 469 - PDF output doesn't use a monospaced font for .Bd -literal
 470   Example: "mandoc -Tpdf afterboot.8 > output.pdf && pdfviewer output.pdf".
 471   Search the text "Routing tables".
 472   Also check what PostScript mode does when fixing this.
 473   reported by juanfra@ Wed, 04 Jun 2014 21:44:58 +0200
 474   instructions from juanfra@  Wed, 11 Jun 2014 02:21:01 +0200
 475     add a new <</Type /Font>> block to the PDF files with /BaseFont /Courier
 476     and change the /Name from /F0 to the new font (/F5 (?)).
 477   re-reported by tb@ Mon, 16 Mar 2015 16:47:21 +0100
 478   loc **  exist **  algo **  size *  imp **
 479
 480 --- HTML issues --------------------------------------------------------
 481
 482 - make the HTML scaffolding customozable with -O skip=...
 483   mail to Oliver Corff  3 Jun 2021 17:28:02 +0200
 484   more feedback from Oliver  3 Jun 2021 18:27:56 +0200
 485   more feedback from Oliver  3 Jun 2021 23:37:18 +0200
 486
 487 - .Bd -unfilled should not use monospaced font
 488   anton@  4 Mar 2021 08:19:35 +0100
 489   loc **  exist *  algo *  size *  imp **
 490
 491 - HTML formatting of .nf should avoid <br/>
 492   and not close and re-open <pre> on .P
 493   my mail to ports@ 27 Jun 2021 16:09:20 +0200
 494   loc **  exist **  algo *  size *  imp **
 495
 496 - get rid of the last handful of style= attributes such that
 497   Content-Security-Policy: can be enabled without unsafe-inline
 498   suggested by bentley@  Nov 10, 2019 at 06:02:49AM -0700
 499   loc *  exist *  algo *  size *  imp **
 500
 501 - .Bf at the beginning of a paragraph inserts a bogus 1ex horizontal
 502   space, see for example random(3).  Introduced in
 503   http://mdocml.bsd.lv/cgi-bin/cvsweb/mdoc_html.c.diff?r1=1.91&r2=1.92
 504   reported by deraadt@ Mon, 28 Sep 2015 20:14:13 -0600 (MDT)
 505   loc **  exist **  algo **  size *  imp *
 506
 507 - jsg on icb, Nov 3, 2014:
 508   try to guess Xr in man(7) for hyperlinking
 509   and render them with <a class="Xr" href=...>
 510   https://github.com/Debian/debiman/issues/15
 511   loc *  exist *  algo **  size **  imp **
 512
 513 - space characters can end up in href= attributes, for example coming
 514   from the first .Xr argument (where they make no sense, but still);
 515   does this affect other characters, other source macros...?
 516   Jackson Pauls  29 Aug 2017 16:56:27 +0100
 517
 518 - The tables used to render the three-part page headers actually force
 519   the width of the <body> to the max-width given for <html>.
 520   Not yet sure how to fix that...
 521   Observed by an Anonymous Coward on undeadly.org:
 522   http://undeadly.org/cgi?action=article&sid=20140925064244&pid=1
 523   loc *  exist *  algo **  size *  imp ***
 524
 525 - generate <img> tags in HTML
 526   idea from florian@  Tue, 7 Apr 2015 00:26:28 +0000
 527   may be possible to implement with .Lk img://something.png alt_text
 528
 529 - check https://github.com/trentm/mdocml
 530
 531 ************************************************************************
 532 * formatting issues: gratuitous differences
 533 ************************************************************************
 534
 535 - .Fn reopens a new scope after punctuation in mandoc,
 536   but closes its scope for good in groff.
 537   Do we want to change mandoc or groff?
 538   Steffen Nurpmeso  Sat, 08 Nov 2014 13:34:59 +0100
 539   loc *  exist **  algo **  size *  imp **
 540
 541 - In .Bl -enum -width 0n, groff continues one the same line after
 542   the number, mandoc breaks the line.
 543   mail to kristaps@  Mon, 20 Jul 2009 02:21:39 +0200
 544   loc *  exist **  algo **  size *  imp **
 545
 546 - .Pp between two .It in .Bl -column should produce one,
 547   not two blank lines, see e.g. login.conf(5).
 548   reported by jmc@  Sun, 17 Apr 2011 14:04:58 +0059
 549   reported again by sthen@  Wed, 18 Jan 2012 02:09:39 +0000 (UTC)
 550   loc *  exist ***  algo **  size *  imp **
 551
 552 - If the *first* line after .It is .Pp, break the line right after
 553   the tag, do not pad with space characters before breaking.
 554   See the description of the a, c, and i commands in sed(1).
 555   loc *  exist **  algo **  size *  imp **
 556
 557 - If the first line after .It is .D1, do not assert a blank line
 558   in between, see for example tmux(1).
 559   reported by nicm@  13 Jan 2011 00:18:57 +0000
 560   loc *  exist **  algo **  size *  imp **
 561
 562 - Trailing punctuation after .It should trigger EOS spacing.
 563   reported by Nicolas Joly  Sat, 17 Nov 2012 11:49:54 +0100
 564   Probably, this should be fixed somewhere in termp_it_pre(), not sure.
 565   loc *  exist **  algo **  size *  imp **
 566
 567 - When the -width string contains macros, the macros must be rendered
 568   before measuring the width, for example
 569     .Bl -tag -width ".Dv message"
 570   in magic(5), located in src/usr.bin/file, is the same
 571   as -width 7n, not -width 11n.
 572   The same applies to .Bl -column column widths;
 573   reported again by Nicolas Joly Thu, 1 Mar 2012 13:41:26 +0100 via wiz@ 5 Mar
 574   reported again by Franco Fichtner Fri, 27 Sep 2013 21:02:28 +0200
 575   reported again by Bruce Evans Fri, 17 Feb 2017 21:22:44 +0100 via bapt@
 576   loc ***  exist ***  algo ***  size **  imp ***
 577   An easy partial fix would be to just skip the first word if it starts
 578   with a dot, including any following white space, when measuring.
 579   loc *  exist *  algo *  size *  imp ***
 580
 581 - The \& zero-width character counts as output.
 582   That is, when it is alone on a line between two .Pp,
 583   we want three blank lines, not two as in mandoc.
 584   loc **  exist **  algo **  size *  imp **
 585
 586 - Sequences of multiple man(7) paragraphs (.PP, .IP) interspersed
 587   with .ps and .nf/.fi produce execessive blank lines, see libJudy
 588   and graphics/dcmtk.  The parser reorg may help with this.
 589
 590 - trailing whitespace must be ignored even when followed by a font escape,
 591   see for example
 592     makes
 593     \fBdig \fR
 594     operate in batch mode
 595   in dig(1).
 596   loc **  exist **  algo **  size *  imp **
 597
 598 ************************************************************************
 599 * warning issues
 600 ************************************************************************
 601
 602 - shorten/simplify error messages for usage errors
 603   To: deraadt@ 25 Oct 2020 23:37:01 +0100
 604   loc **  exist *  algo *  size **  imp ***
 605
 606 - warn about duplicate .Sh/.Ss heads
 607   gre(4): Rename duplicate sections 20 Apr 2018 15:27:33 +0200
 608   loc *  exist *  algo *  size *  imp **
 609
 610 - style message about macros inside .Bd -literal and .Dl, in particular
 611   font changing macros like .Cm, .Ar, .Fa (from the mdoclint TODO)
 612
 613 - style message about mismatches between the section number in the
 614   file name (if it is known) and the section number in .Dt
 615   (from the mdoclint TODO)
 616
 617 - style message about NULL without .Dv (from the mdoclint TODO)
 618
 619 - style message about error constants without .Er (from the mdoclint TODO)
 620
 621 - warn when .Sh or .Ss contain other macros
 622   Steffen Nurpmeso, savannah.gnu.org/bugs/index.php?45034
 623   loc *  exist *  algo *  size *  imp **
 624
 625 - style message about violations of the convention
 626   .An name Aq Mt localpart@domain in AUTHORS (from the mdoclint TODO)
 627
 628 - warn about attempts to call non-callable macros
 629   Steffen Nurpmeso  Tue, 11 Nov 2014 22:55:16 +0100
 630   Note that formatting is inconsistent in groff.
 631   .Fn Po prints "Po()", .Ar Sh prints "file ..." and no "Sh".
 632   Relatively hard because the relevant code is scattered
 633   all over mdoc_macro.c and all subtly different.
 634   loc **  exist **  algo **  size **  imp **
 635
 636 - warn about punctuation - e.g. ',' and ';' - at the beginning
 637   of a text line, if it is likely intended to follow the preceding
 638   output without intervening whitespace, in particular after a
 639   macro line (from the mdoclint TODO)
 640
 641 - report double .TH in man(7) as an ERROR and let the first win
 642   kristaps@  28 Mar 2021 13:30:41 +0200
 643   loc *  exist *  algo *  size *  imp *
 644
 645 - makewhatis -p complains about language subdirectories:
 646   /usr/local/man//ru: Unknown directory part
 647
 648
 649 ************************************************************************
 650 * documentation issues
 651 ************************************************************************
 652
 653 - mark macros as: page structure domain, manual domain, general text domain
 654   is this useful?
 655
 656 - mention /usr/share/misc/mdoc.template in mdoc(7)?
 657
 658 - Is all the content from http://www.std.com/obi/BSD/doc/usd/28.tbl/tbl
 659   covered in tbl(7)?
 660
 661 ************************************************************************
 662 * performance issues
 663 ************************************************************************
 664
 665 - the PDF file is HUGE: this can be reduced by using relative offsets
 666
 667 ************************************************************************
 668 * structural issues
 669 ************************************************************************
 670
 671 - POSIX says in the documentation of sysconf(3) that PATH_MAX
 672   is allowed to be so large that it is a bad idea to use it
 673   for sizing static buffers.  So use dynamic buffers throughout.
 674   See the file test-PATH_MAX.c for details.
 675   Found by Aaron M. Ucko in the GNU Hurd via Bdale Garbee,
 676   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=829624
 677
 678 - Is it possible to further simplify ENDBODY_SPACE?
 679
 680 - Find better ways to prevent endless loops
 681   in roff(7) macro and string expansion.
 682
 683 - make buffers for parsing functions const
 684   christos@ via wiz@  Fri, 18 Dec 2015 17:10:01 +0100
 685
 686 - struct mparse refactoring
 687   Steffen Nurpmeso  Thu, 04 Sep 2014 12:50:00 +0200
 688
 689 ************************************************************************
 690 * CGI issues
 691 ************************************************************************
 692
 693  - Inspect httpd(8) logs on man.openbsd.org and consider
 694    whether logging can be improved, where bad syntax comes from,
 695    and what needs to be done to get rid of COMPAT_OLDURI.
 696  - Enable HTTP compression by detecting gzip encoding and filtering
 697    output through libz.
 698  - Privilege separation (see OpenSSH).
 699  - Enable caching support via HTTP 304 and If-Modified-Since.
 700
 701 ************************************************************************
 702 * to improve in the groff_mdoc(7) macros
 703 ************************************************************************
 704
 705 - delete OS release verification from .Dx, .Fx, .Nx, .Ox etc.
 706   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=629161
 707   also Branden Robinson 18 Dec 2019 00:59:52 +1100
 708
 709 - Can the distinction between .Vt and .Va be made stricter,
 710   recommending .Vt extern char * Ns Va optarg ; ?
 711   What about the block macro properties of .Vt in the SYNOPSIS?
 712   zeurkous 25 Dec 2019 08:48:36 +0100
 713
 714 - .Cd # arch1, arch2 in section 4 pages:
 715   find better way to indicate multiple architectures, maybe:
 716   allow .Dt vgafb 4 "macppc sparc64"
 717   already shown as "Device Drivers Manual (macppc sparc64)"
 718   for apropos, make that "vgafb(4) - macppc # sparc64" instead of "- all"
 719   groff can be made to show multiple arches, too, but it is
 720   tedious to do the string parsing in roff code...
 721   jmc@ 23 Apr 2018 07:24:52 +0100 [man for vgafb(4)...]
 722   loc **  exist **  algo *  size *  imp ***
 723
 724 - use uname(1) to set doc-default-operating-system at install time
 725   tobimensch  Mon, 1 Dec 2014 00:25:07 +0100
 726
 727 - apostrophe (39), circumflex (94), grave (96), tilde (126)
 728   in manuals: \(aq, \(ha, \`, \(ti
 729   Re: [Groff] ASCII Minus Sign in man Pages.
 730   bentley@ 26 Apr 2017 10:02:06 -0600
 731   Do we need to fix existing manuals?
 732   Do we need to fix the definition of the mdoc(7) language?