Bug#871225: Man.pm: False point size changes

[Bjarni Ingi Gislason]

Package: perl-modules-5.26
Version: 5.26.0-5
Severity: minor
Tags: patch

Dear Maintainer,

   * What led up to the situation?

"man gcc" with

MAN_KEEP_STDERR=yes
MANOPT=--encoding=latin1 --no-hyphenation --warnings=w --no-justification
MANWIDTH=80

   * What was the outcome of this action?

<standard input>:3310: warning: \s escape results in non-positive point size; set to 1
<standard input>:3311: warning: \s escape results in non-positive point size; set to 1
<standard input>:25: backtrace: string `C+'
<standard input>:3311: warning: \s escape results in non-positive point size; set to 1
<standard input>:3320: warning: \s escape results in non-positive point size; set to 1
<standard input>:3323: warning: \s escape results in non-positive point size; set to 1
<standard input>:3326: warning: \s escape results in non-positive point size; set to 1
<standard input>:3331: warning: \s escape results in non-positive point size; set to 1
<standard input>:3333: warning: \s escape results in non-positive point size; set to 1
<standard input>:3333: warning: \s escape results in non-positive point size; set to 1
<standard input>:3336: warning: \s escape results in non-positive point size; set to 1
<standard input>:3337: warning: \s escape results in non-positive point size; set to 1
<standard input>:4668: warning: \s escape results in non-positive point size; set to 1
<standard input>:25: backtrace: string `C+'
<standard input>:4668: warning: \s escape results in non-positive point size; set to 1
<standard input>:4670: backtrace
/home/bg/git/groff/tmac/an-old.tmac:493: backtrace: macro `IP'
<standard input>:4670: warning: \s escape results in non-positive point size; set to 1
<standard input>:4670: backtrace
/home/bg/git/groff/tmac/an-old.tmac:493: backtrace: macro `IP'
<standard input>:4670: warning: \s escape results in non-positive point size; set to 1
<standard input>:9001: warning [p 93, 4.5i]: can't break line
<standard input>:9023: warning [p 93, 8.2i]: can't break line
<standard input>:9234: warning [p 95, 7.3i]: can't break line

   * What outcome did you expect instead?

  No warnings

  The escape '\s0' does not get the right former size if another '\s0' comes
after it (like '\s-1...\s-2...\s0...\s0').

  The string '\*(C+' gets resized in the manual for "gcc" in some lines.
  Each use of this string gets the previous size smaller, the warning is not
issued until the size is down to less than 1 point.

Patch:

--- Man.pm	2017-07-30 16:15:47.000000000 +0000
+++ Man.pm.new	2017-08-07 00:03:59.000000000 +0000
@@ -527,7 +527,7 @@ sub guesswork {
             ( [A-Z] [A-Z] (?: \s? [/A-Z+:\d_\$&] | \\- | \s? [.,\"] )* )  # (2)
             (?= [\s>\}\]\(\)\'\".?!,;] | \\*\(-- | \\[ ] | $ )            # (3)
         } {
-            $1 . '\s-1' . $2 . '\s0'
+            $1 . '\s-1' . $2 . '\s+1'
         }egx;
     }
 
@@ -1521,7 +1521,7 @@ sub preamble_template {
 .\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
 .\" nothing in troff, for use with C<>.
 .tr \(*W-
-.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s+2\v'.1v'\h'-1p'
 .ie n \{\
 .    ds -- \(*W-
 .    ds PI pi

-- System Information:
Debian Release: buster/sid
  APT prefers proposed-updates
  APT policy: (500, 'proposed-updates'), (500, 'testing'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.30-2u2 (SMP w/2 CPU cores)
Locale: LANG=is_IS.iso88591, LC_CTYPE=is_IS.iso88591 (charmap=ISO-8859-1), LANGUAGE=is_IS.iso88591 (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages perl-modules-5.26 depends on:
ii  dpkg       1.18.24
ii  perl-base  5.26.0-5

Versions of packages perl-modules-5.26 recommends:
ii  perl  5.26.0-5

perl-modules-5.26 suggests no packages.

-- no debconf information

-- 
Bjarni I. Gislason