improve ruby-2.5 compatibility (epel8)

An unfortunate bug in rdoc-5.0 causes a build failure on epel8.  This is
fixed in ruby-2.6/rdoc-6.0.2¹.  Until/unless the fix is backported to
RHEL-8 (which seems unlikely), we can only patch around this.

Thanks, as usual, to Dan Allen for going above and beyond to patch this
upstream.

¹ https://github.com/ruby/rdoc/pull/586
  https://github.com/ruby/rdoc/commit/a1631aa

0001-use-single-line-block-in-manify-method-in-manpage-co.patch

@@ -0,0 +1,25 @@
+From cc9a8d3cd12f2c15e43bd263b8b8a9b32d097831 Mon Sep 17 00:00:00 2001
+From: Dan Allen <dan.j.allen@gmail.com>
+Date: Thu, 25 May 2023 18:39:56 -0600
+Subject: [PATCH] use single-line block in manify method in manpage converter
+ to make it easier to patch
+
+---
+ lib/asciidoctor/converter/manpage.rb | 4 +---
+ 1 file changed, 1 insertion(+), 3 deletions(-)
+
+diff --git a/lib/asciidoctor/converter/manpage.rb b/lib/asciidoctor/converter/manpage.rb
+index bcf2b784..a7aba996 100644
+--- a/lib/asciidoctor/converter/manpage.rb
++++ b/lib/asciidoctor/converter/manpage.rb
+@@ -716,9 +716,7 @@ def manify str, opts = {}
+       .gsub(LiteralBackslashRx) { $1 ? $& : '\\(rs' } # literal backslash (not a troff escape sequence)
+       .gsub(EllipsisCharRefRx, '...') # horizontal ellipsis
+       .gsub(LeadingPeriodRx, '\\\&.') # leading . is used in troff for macro call or other formatting; replace with \&.
+-      .gsub(EscapedMacroRx) do # drop orphaned \c escape lines, unescape troff macro, quote adjacent character, isolate macro line
+-        (rest = $3.lstrip).empty? ? %(.#{$1}"#{$2}") : %(.#{$1}"#{$2.rstrip}"#{LF}#{rest})
+-      end
++      .gsub(EscapedMacroRx) { (rest = $3.lstrip).empty? ? %(.#{$1}"#{$2}") : %(.#{$1}"#{$2.rstrip}"#{LF}#{rest}) } # drop orphaned \c escape lines, unescape troff macro, quote adjacent character, isolate macro line
+       .gsub('-', '\-')
+       .gsub('&lt;', '<')
+       .gsub('&gt;', '>')

0002-change-dot-layout-in-chained-method-call-to-be-compa.patch

@@ -0,0 +1,85 @@
+From b7c03964cfc96af9ced5db3c1a6c7a7663de5cb2 Mon Sep 17 00:00:00 2001
+From: Dan Allen <dan.j.allen@gmail.com>
+Date: Fri, 26 May 2023 01:44:09 -0600
+Subject: [PATCH] change dot layout in chained method call to be compatible
+ with rdoc generator from Ruby 2.5
+
+---
+ lib/asciidoctor/converter/manpage.rb | 64 ++++++++++++++--------------
+ 1 file changed, 32 insertions(+), 32 deletions(-)
+
+diff --git a/lib/asciidoctor/converter/manpage.rb b/lib/asciidoctor/converter/manpage.rb
+index a7aba996..be52e9be 100644
+--- a/lib/asciidoctor/converter/manpage.rb
++++ b/lib/asciidoctor/converter/manpage.rb
+@@ -712,38 +712,38 @@ def manify str, opts = {}
+     else
+       str = str.tr_s WHITESPACE, ' '
+     end
+-    str = str
+-      .gsub(LiteralBackslashRx) { $1 ? $& : '\\(rs' } # literal backslash (not a troff escape sequence)
+-      .gsub(EllipsisCharRefRx, '...') # horizontal ellipsis
+-      .gsub(LeadingPeriodRx, '\\\&.') # leading . is used in troff for macro call or other formatting; replace with \&.
+-      .gsub(EscapedMacroRx) { (rest = $3.lstrip).empty? ? %(.#{$1}"#{$2}") : %(.#{$1}"#{$2.rstrip}"#{LF}#{rest}) } # drop orphaned \c escape lines, unescape troff macro, quote adjacent character, isolate macro line
+-      .gsub('-', '\-')
+-      .gsub('&lt;', '<')
+-      .gsub('&gt;', '>')
+-      .gsub('&#43;', '+')       # plus sign; alternately could use \c(pl
+-      .gsub('&#160;', '\~')     # non-breaking space
+-      .gsub('&#169;', '\(co')   # copyright sign
+-      .gsub('&#174;', '\(rg')   # registered sign
+-      .gsub('&#8482;', '\(tm')  # trademark sign
+-      .gsub('&#176;', '\(de')   # degree sign
+-      .gsub('&#8201;', ' ')     # thin space
+-      .gsub('&#8211;', '\(en')  # en dash
+-      .gsub(EmDashCharRefRx, '\(em') # em dash
+-      .gsub('&#8216;', '\(oq')  # left single quotation mark
+-      .gsub('&#8217;', '\(cq')  # right single quotation mark
+-      .gsub('&#8220;', '\(lq')  # left double quotation mark
+-      .gsub('&#8221;', '\(rq')  # right double quotation mark
+-      .gsub('&#8592;', '\(<-')  # leftwards arrow
+-      .gsub('&#8594;', '\(->')  # rightwards arrow
+-      .gsub('&#8656;', '\(lA')  # leftwards double arrow
+-      .gsub('&#8658;', '\(rA')  # rightwards double arrow
+-      .gsub('&#8203;', '\:')    # zero width space
+-      .gsub('&amp;', '&')       # literal ampersand (NOTE must take place after any other replacement that includes &)
+-      .gsub('\'', '\*(Aq')      # apostrophe / neutral single quote
+-      .gsub(MockMacroRx, '\1')  # mock boundary
+-      .gsub(ESC_BS, '\\')       # unescape troff backslash (NOTE update if more escapes are added)
+-      .gsub(ESC_FS, '.')        # unescape full stop in troff commands (NOTE must take place after gsub(LeadingPeriodRx))
+-      .rstrip                   # strip trailing space
++    str = str.
++      gsub(LiteralBackslashRx) { $1 ? $& : '\\(rs' }. # literal backslash (not a troff escape sequence)
++      gsub(EllipsisCharRefRx, '...'). # horizontal ellipsis
++      gsub(LeadingPeriodRx, '\\\&.'). # leading . is used in troff for macro call or other formatting; replace with \&.
++      gsub(EscapedMacroRx) { (rest = $3.lstrip).empty? ? %(.#{$1}"#{$2}") : %(.#{$1}"#{$2.rstrip}"#{LF}#{rest}) }. # drop orphaned \c escape lines, unescape troff macro, quote adjacent character, isolate macro line
++      gsub('-', '\-').
++      gsub('&lt;', '<').
++      gsub('&gt;', '>').
++      gsub('&#43;', '+').      # plus sign; alternately could use \c(pl
++      gsub('&#160;', '\~').    # non-breaking space
++      gsub('&#169;', '\(co').  # copyright sign
++      gsub('&#174;', '\(rg').  # registered sign
++      gsub('&#8482;', '\(tm'). # trademark sign
++      gsub('&#176;', '\(de').  # degree sign
++      gsub('&#8201;', ' ').    # thin space
++      gsub('&#8211;', '\(en'). # en dash
++      gsub(EmDashCharRefRx, '\(em'). # em dash
++      gsub('&#8216;', '\(oq'). # left single quotation mark
++      gsub('&#8217;', '\(cq'). # right single quotation mark
++      gsub('&#8220;', '\(lq'). # left double quotation mark
++      gsub('&#8221;', '\(rq'). # right double quotation mark
++      gsub('&#8592;', '\(<-'). # leftwards arrow
++      gsub('&#8594;', '\(->'). # rightwards arrow
++      gsub('&#8656;', '\(lA'). # leftwards double arrow
++      gsub('&#8658;', '\(rA'). # rightwards double arrow
++      gsub('&#8203;', '\:').   # zero width space
++      gsub('&amp;', '&').      # literal ampersand (NOTE must take place after any other replacement that includes &)
++      gsub('\'', '\*(Aq').     # apostrophe / neutral single quote
++      gsub(MockMacroRx, '\1'). # mock boundary
++      gsub(ESC_BS, '\\').      # unescape troff backslash (NOTE update if more escapes are added)
++      gsub(ESC_FS, '.').       # unescape full stop in troff commands (NOTE must take place after gsub(LeadingPeriodRx))
++      rstrip                   # strip trailing space
+     opts[:append_newline] ? %(#{str}#{LF}) : str
+   end
+ 

rubygem-asciidoctor.spec

@@ -7,10 +7,16 @@
 Summary: A fast, open source AsciiDoc implementation in Ruby
 Name: rubygem-%{gem_name}
 Version: 2.0.20
-Release: 1%{?dist}
+Release: 2%{?dist}
 License: MIT
 URL: https://asciidoctor.org
 Source0: https://github.com/asciidoctor/asciidoctor/archive/%{gittag}/%{gem_name}-%{version}%{pre}.tar.gz
+# improve ruby-2.5 compatibility
+# https://github.com/asciidoctor/asciidoctor/issues/4462
+# https://github.com/asciidoctor/asciidoctor/commit/cc9a8d3c
+Patch0: 0001-use-single-line-block-in-manify-method-in-manpage-co.patch
+# https://github.com/asciidoctor/asciidoctor/commit/b7c03964
+Patch1: 0002-change-dot-layout-in-chained-method-call-to-be-compa.patch
 %if 0%{?el7}
 Requires: ruby(release)
 BuildRequires: ruby(release)
@@ -121,6 +127,9 @@ cp -a .%{gem_instdir}/man/*.1 \
 %doc %{gem_docdir}
 
 %changelog
+* Thu May 25 2023 Todd Zullinger <tmz@pobox.com> - 2.0.20-2
+- improve ruby-2.5 compatibility (epel8)
+
 * Thu May 18 2023 Todd Zullinger <tmz@pobox.com> - 2.0.20-1
 - update to asciidoctor 2.0.20 (rhbz#2208089)