[groff] 01/01: Simplify behaviour of .Bl -tag

[Carsten Kunze]

carstenkunze pushed a commit to branch master
in repository groff.

commit aa28f0c99880e14a9ca024495022db908343eec1
Author: Ingo Schwarze <address@hidden>
Date:   Sat Oct 8 21:27:34 2016 +0200

    Simplify behaviour of .Bl -tag
    
    See https://savannah.gnu.org/bugs/index.php?49272
---
 ChangeLog             |   28 ++++++++++++++++++++++++++
 tmac/doc.tmac-u       |   53 +------------------------------------------------
 tmac/groff_mdoc.7.man |   10 ++--------
 3 files changed, 31 insertions(+), 60 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 62f7ded..0dbb19a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,31 @@
+2016-10-05  Ingo Schwarze  <address@hidden>
+
+       * tmac/doc.tmac-u: Simplify behaviour of .Bl -tag
+       * tmac/groff_mdoc.7.man: Update documentation to the new
+       behaviour of .Bl -tag
+
+       If an mdoc(7) .Bl -tag macro lacks the -width argument, the
+       body indentation is calculated separately for each child .It
+       macro.  Neither the Heirloom nor the mandoc(1) implementation
+       of the mdoc(7) language show such behaviour; both use a
+       constant default width for the whole list in that case.
+
+       Apart from doubts whether lists with variable indentation are
+       typographically sound in the first place, support for variable
+       widths in groff is so restricted that it's practically
+       useless.  For each .It, the width will be the default width of
+       whatever happens to be the leading macro after the .It, or of
+       .No if .It is not followed by a macro.
+
+       See
+
+       https://savannah.gnu.org/bugs/index.php?49272
+
+       and
+
+       http://lists.gnu.org/archive/html/groff/2016-10/msg00006.html
+
+
 2016-09-09  Werner LEMBERG  <address@hidden>
 
        * tmac/sv.tmac: Fix `.hy' settings (#48904).
diff --git a/tmac/doc.tmac-u b/tmac/doc.tmac-u
index 8b351b4..93d5248 100644
--- a/tmac/doc.tmac-u
+++ b/tmac/doc.tmac-u
@@ -2990,6 +2990,7 @@
 .  \}
 .  el \{ .ie "\$1"-tag" \{\
 .    ds doc-list-type-stack\n[doc-list-depth] tag-list
+.    nr doc-list-indent-stack\n[doc-list-depth] 6n
 .    nr doc-list-have-indent-stack\n[doc-list-depth] 1
 .  \}
 .  el \{ .ie "\$1"-item" \{\
@@ -3105,7 +3106,6 @@
 .\" NS   doc-list-offset-stackXXX
 .\" NS   doc-num-columns
 .\" NS   doc-tag-prefix-stackXXX
-.\" NS   doc-tag-width-stackXXX
 .\" NS
 .\" NS local variables:
 .\" NS   doc-box-dBla
@@ -3148,8 +3148,6 @@
 .
 .  el \{ .ie "\*[doc-arg\n[doc-arg-ptr]]"-width" \{\
 .    nr doc-arg-ptr +1
-.    ds doc-tag-width-stack\n[doc-list-depth] TagwidtH
-.
 .    ds doc-str-dBla "\*[doc-arg\n[doc-arg-ptr]]
 .    substring doc-str-dBla 0 0
 .    ie .\*[doc-str-dBla] \{\
@@ -3394,7 +3392,6 @@
 .    nr doc-list-indent-stack\n[doc-reg-dsgv]-saved 
\n[doc-list-indent-stack\n[doc-reg-dsgv]]
 .    nr doc-compact-list-stack\n[doc-reg-dsgv]-saved 
\n[doc-compact-list-stack\n[doc-reg-dsgv]]
 .    ds doc-tag-prefix-stack\n[doc-reg-dsgv]-saved 
"\*[doc-tag-prefix-stack\n[doc-reg-dsgv]]
-.    ds doc-tag-width-stack\n[doc-reg-dsgv]-saved 
"\*[doc-tag-width-stack\n[doc-reg-dsgv]]
 .    nr doc-list-offset-stack\n[doc-reg-dsgv]-saved 
\n[doc-list-offset-stack\n[doc-reg-dsgv]]
 .    nr doc-enum-list-count-stack\n[doc-reg-dsgv]-saved 
\n[doc-enum-list-count-stack\n[doc-reg-dsgv]]
 .    nr doc-reg-dsgv +1
@@ -3538,7 +3535,6 @@
 .    nr doc-list-indent-stack\n[doc-reg-drgv] 
\n[doc-list-indent-stack\n[doc-reg-drgv]-saved]
 .    nr doc-compact-list-stack\n[doc-reg-drgv] 
\n[doc-compact-list-stack\n[doc-reg-drgv]-saved]
 .    ds doc-tag-prefix-stack\n[doc-reg-drgv] 
"\*[doc-tag-prefix-stack\n[doc-reg-drgv]-saved]
-.    ds doc-tag-width-stack\n[doc-reg-drgv] 
"\*[doc-tag-width-stack\n[doc-reg-drgv]-saved]
 .    nr doc-list-offset-stack\n[doc-reg-drgv] 
\n[doc-list-offset-stack\n[doc-reg-drgv]-saved]
 .    nr doc-enum-list-count-stack\n[doc-reg-drgv] 
\n[doc-enum-list-count-stack\n[doc-reg-drgv]-saved]
 .    nr doc-reg-drgv +1
@@ -4030,13 +4026,6 @@
 .  ev
 .  box
 .
-.  if !"TagwidtH"\*[doc-tag-width-stack\n[doc-list-depth]]" \{\
-.    if !\n[doc-list-have-indent-stack\n[doc-list-depth]] \{\
-.      in -(\n[doc-list-indent-stack\n[doc-list-depth]]u + 
\n[doc-digit-width]u)
-.      nr doc-list-have-indent-stack\n[doc-list-depth] 1
-.    \}
-.    doc-get-tag-width
-.  \}
 .  doc-set-vertical-and-indent 1
 .  nr doc-reg-dtl (\n[doc-list-indent-stack\n[doc-list-depth]]u + 
\n[doc-digit-width]u)
 .  ti -\n[doc-reg-dtl]u
@@ -4064,29 +4053,6 @@
 ..
 .
 .
-.\" NS doc-get-tag-width macro
-.\" NS   resolve unknown tag width (`tag' list-type only)
-.\" NS
-.\" NS modifies:
-.\" NS   doc-list-indent-stackXXX
-.\" NS   doc-tag-width-stackXXX
-.\" NS
-.\" NS requires:
-.\" NS   doc-curr-arg
-.\" NS   doc-curr-type
-.
-.de doc-get-tag-width
-.  ie (\n[doc-curr-type] == 1) \{\
-.    ds doc-tag-width-stack\n[doc-list-depth] \*[doc-curr-arg]
-.    nr doc-list-indent-stack\n[doc-list-depth] \n[\*[doc-curr-arg]]
-.  \}
-.  el \{\
-.    ds doc-tag-width-stack\n[doc-list-depth] No
-.    nr doc-list-indent-stack\n[doc-list-depth] \n[No]
-.  \}
-..
-.
-.
 .\" NS doc-set-vertical-and-indent macro
 .\" NS   set up vertical spacing (if not compact) and indentation (with
 .\" NS   offset if argument is non-zero)
@@ -4139,19 +4105,6 @@
 .ds doc-tag-prefix-stack1
 .
 .
-.\" NS doc-tag-width-stackXXX global string
-.\" NS   stack of strings indicating how to set up current element of
-.\" NS   doc-list-indent-stackXXX -- if set to TagwidtH, user has set it
-.\" NS   directly; if it is a macro name, use the macro's width value;
-.\" NS   otherwise, `doc-get-tag-width' uses width value of `No'.
-.\" NS
-.\" NS limit:
-.\" NS   doc-list-depth
-.
-.ds doc-tag-width-stack0
-.ds doc-tag-width-stack1
-.
-.
 .\" NS doc-list-offset-stackXXX global register
 .\" NS   stack of list offsets
 .\" NS
@@ -4193,7 +4146,6 @@
 .\" NS   doc-list-offset-stackXXX
 .\" NS   doc-list-type-stackXXX
 .\" NS   doc-tag-prefix-stackXXX
-.\" NS   doc-tag-width-stackXXX
 .\" NS   doc-enum-list-count-stackXXX
 .\" NS
 .\" NS local variables:
@@ -4205,7 +4157,6 @@
 .  nr doc-list-indent-stack\n[doc-reg-dils] 0
 .  nr doc-list-offset-stack\n[doc-reg-dils] 0
 .  ds doc-tag-prefix-stack\n[doc-reg-dils]
-.  ds doc-tag-width-stack\n[doc-reg-dils] 
\*[doc-tag-width-stack\n[doc-list-depth]]
 .  ds doc-list-type-stack\n[doc-reg-dils]
 .  nr doc-compact-list-stack\n[doc-reg-dils] 0
 .  nr doc-enum-list-count-stack\n[doc-reg-dils] 0
@@ -4222,7 +4173,6 @@
 .\" NS   doc-list-offset-stackXXX
 .\" NS   doc-list-type-stackXXX
 .\" NS   doc-tag-prefix-stackXXX
-.\" NS   doc-tag-width-stackXXX
 .\" NS   doc-enum-list-count-stackXXX
 .
 .de doc-decrement-list-stack
@@ -4231,7 +4181,6 @@
 .  nr doc-list-indent-stack\n[doc-list-depth] 0
 .  nr doc-list-offset-stack\n[doc-list-depth] 0
 .  ds doc-tag-prefix-stack\n[doc-list-depth]
-.  ds doc-tag-width-stack\n[doc-list-depth]
 .  nr doc-compact-list-stack\n[doc-list-depth] 0
 .  nr doc-enum-list-count-stack\n[doc-list-depth] 0
 ..
diff --git a/tmac/groff_mdoc.7.man b/tmac/groff_mdoc.7.man
index 12416da..5968d0b 100644
--- a/tmac/groff_mdoc.7.man
+++ b/tmac/groff_mdoc.7.man
@@ -3925,14 +3925,8 @@ the width of
 .Aq Ar string
 (typeset with a fixed-width font) is taken as the width.
 .Pp
-If a width is not specified for the tag list type, every time
-.Ql .It
-is invoked, an attempt is made to determine an appropriate width.
-If the first argument to
-.Ql .It
-is a callable macro, the default width for that macro will be used;
-otherwise, the default width of
-.Ql .No
+If a width is not specified for the tag list type,
+.Sq 6n
 is used.
 .It Fl offset Ao Ar string Ac
 If