resolves #4458 process constrained inline passthrough inside monospace span (PR #4459)

4 files changed, 55 insertions, 39 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index d436a1c0..7a188ef1 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -73,6 +73,7 @@ Improvements::
 
 Bug Fixes::
 
+  * Process constrained inline passthrough inside monospace span (#4458)
   * Catalog inline ref defined using anchor macro even when resolved reftext is empty
   * Use while loop rather than recursion to locate next line to process; prevents stack limit error (#4368)
   * Avoid numeric character reference when looking for fragment in target of xref (#4393, #3642)
diff --git a/lib/asciidoctor/rx.rb b/lib/asciidoctor/rx.rb
index 39fb0fd3..2fabe0dc 100644
--- a/lib/asciidoctor/rx.rb
+++ b/lib/asciidoctor/rx.rb
@@ -569,23 +569,17 @@ module Asciidoctor
   # Examples
   #
   #   +text+
-  #   `text` (compat)
+  #   [x-]+text+
+  #   [x-]`text`
+  #   `text` (compat only)
+  #   [role]`text` (compat only)
   #
   # NOTE we always capture the attributes so we know when to use compatible (i.e., legacy) behavior
   InlinePassRx = {
-    false => ['+', '`', /(^|[^#{CC_WORD};:])(?:#{QuoteAttributeListRxt})?(\\?(\+|`)(\S|\S#{CC_ALL}*?\S)\4)(?!#{CG_WORD})/m],
-    true => ['`', nil, /(^|[^`#{CC_WORD}])(?:#{QuoteAttributeListRxt})?(\\?(`)([^`\s]|[^`\s]#{CC_ALL}*?\S)\4)(?![`#{CC_WORD}])/m],
+    false => ['+', '-]', /((?:^|[^#{CC_WORD};:\\])(?=(\[)|\+)|\\(?=\[)|(?=\\\+))(?:\2(x-|[^\[\]]+ x-)\]|(?:#{QuoteAttributeListRxt})?(?=(\\)?\+))(\5?(\+|`)(\S|\S#{CC_ALL}*?\S)\7)(?!#{CG_WORD})/m],
+    true => ['`', nil, /(^|[^`#{CC_WORD}])(?:(\Z)()|#{QuoteAttributeListRxt}(?=(\\))?)?(\5?(`)([^`\s]|[^`\s]#{CC_ALL}*?\S)\7)(?![`#{CC_WORD}])/m],
   }
 
-  # Matches an inline plus passthrough spanning multiple lines, but only when it occurs directly
-  # inside constrained monospaced formatting in non-compat mode.
-  #
-  # Examples
-  #
-  #   +text+
-  #
-  SinglePlusInlinePassRx = /^(\\)?\+(\S|\S#{CC_ALL}*?\S)\+$/m
-
   # Matches several variants of the passthrough inline macro, which may span multiple lines.
   #
   # Examples
diff --git a/lib/asciidoctor/substitutors.rb b/lib/asciidoctor/substitutors.rb
index af850790..d88e0d74 100644
--- a/lib/asciidoctor/substitutors.rb
+++ b/lib/asciidoctor/substitutors.rb
@@ -1065,10 +1065,11 @@ module Substitutors
     pass_inline_char1, pass_inline_char2, pass_inline_rx = InlinePassRx[compat_mode]
     text = text.gsub pass_inline_rx do
       preceding = $1
-      attrlist = $2
-      escape_mark = RS if (quoted_text = $3).start_with? RS
-      backtick_mark = $4 == '`'
-      content = $5
+      attrlist = $4 || $3
+      escaped = true if $5
+      quoted_text = $6
+      format_mark = $7
+      content = $8
 
       if compat_mode
         old_behavior = true
@@ -1077,32 +1078,30 @@ module Substitutors
       end
 
       if attrlist
-        if backtick_mark && !old_behavior
-          next extract_inner_passthrough content, %(#{preceding}[#{attrlist}]#{escape_mark})
-        elsif escape_mark
+        if escaped
           # honor the escape of the formatting mark
-          next %(#{preceding}[#{attrlist}]#{old_behavior_forced && backtick_mark ? quoted_text : (quoted_text.slice 1, quoted_text.length)})
+          next %(#{preceding}[#{attrlist}]#{quoted_text.slice 1, quoted_text.length})
         elsif preceding == RS
           # honor the escape of the attributes
-          next %(#{preceding}[#{attrlist}]#{quoted_text}) if old_behavior_forced && backtick_mark
+          next %(#{preceding}[#{attrlist}]#{quoted_text}) if old_behavior_forced && format_mark == '`'
           preceding = %([#{attrlist}])
         elsif old_behavior_forced
           attributes = attrlist == 'x-' ? {} : (parse_quoted_text_attributes attrlist.slice 0, attrlist.length - 3)
         else
           attributes = parse_quoted_text_attributes attrlist
         end
-      elsif backtick_mark && !old_behavior
-        next extract_inner_passthrough content, %(#{preceding}#{escape_mark})
-      elsif escape_mark
+      elsif escaped
         # honor the escape of the formatting mark
         next %(#{preceding}#{quoted_text.slice 1, quoted_text.length})
+      elsif compat_mode && preceding == RS
+        next quoted_text
       end
 
       if compat_mode
         passthrus[passthru_key = passthrus.size] = { text: content, subs: BASIC_SUBS, attributes: attributes, type: :monospaced }
       elsif attributes
         if old_behavior
-          subs = backtick_mark ? BASIC_SUBS : NORMAL_SUBS
+          subs = format_mark == '`' ? BASIC_SUBS : NORMAL_SUBS
           passthrus[passthru_key = passthrus.size] = { text: content, subs: subs, attributes: attributes, type: :monospaced }
         else
           passthrus[passthru_key = passthrus.size] = { text: content, subs: BASIC_SUBS, attributes: attributes, type: :unquoted }
@@ -1400,20 +1399,6 @@ module Substitutors
     end.join LF)
   end
 
-  # Internal: Extract nested single-plus passthrough; otherwise return unprocessed
-  def extract_inner_passthrough text, pre
-    if (text.end_with? '+') && (text.start_with? '+', '\+') && SinglePlusInlinePassRx =~ text
-      if $1
-        %(#{pre}`+#{$2}+`)
-      else
-        @passthroughs[passthru_key = @passthroughs.size] = { text: $2, subs: BASIC_SUBS }
-        %(#{pre}`#{PASS_START}#{passthru_key}#{PASS_END}`)
-      end
-    else
-      %(#{pre}`#{text}`)
-    end
-  end
-
   # Internal: Convert a quoted text region
   #
   # match  - The MatchData for the quoted text region
diff --git a/test/substitutions_test.rb b/test/substitutions_test.rb
index 7b57c6d8..cbb69cbc 100644
--- a/test/substitutions_test.rb
+++ b/test/substitutions_test.rb
@@ -2154,6 +2154,42 @@ context 'Substitutions' do
         assert_equal 'the text <code>asciimath:[x = y]</code> should be passed through as <code>literal</code> text', para.content
       end
 
+      test 'should support constrained passthrough in middle of monospace span' do
+        input = 'a `foo +bar+ baz` kind of thing'
+        para = block_from_string input
+        assert_equal 'a <code>foo bar baz</code> kind of thing', para.content
+      end
+
+      test 'should support constrained passthrough in monospace span preceded by escaped boxed attrlist with transitional role' do
+        input = %(#{BACKSLASH}[x-]`foo +bar+ baz`)
+        para = block_from_string input
+        assert_equal '[x-]<code>foo bar baz</code>', para.content
+      end
+
+      test 'should treat monospace phrase with escaped boxed attrlist with transitional role as monospace' do
+        input = %(#{BACKSLASH}[x-]`*foo* +bar+ baz`)
+        para = block_from_string input
+        assert_equal '[x-]<code><strong>foo</strong> bar baz</code>', para.content
+      end
+
+      test 'should ignore escaped attrlist with transitional role on monospace phrase if not proceeded by [' do
+        input = %(#{BACKSLASH}x-]`*foo* +bar+ baz`)
+        para = block_from_string input
+        assert_equal %(#{BACKSLASH}x-]<code><strong>foo</strong> bar baz</code>), para.content
+      end
+
+      test 'should not process passthrough inside transitional literal monospace span' do
+        input = 'a [x-]`foo +bar+ baz` kind of thing'
+        para = block_from_string input
+        assert_equal 'a <code>foo +bar+ baz</code> kind of thing', para.content
+      end
+
+      test 'should support constrained passthrough in monospace phrase with attrlist' do
+        input = '[.role]`foo +bar+ baz`'
+        para = block_from_string input
+        assert_equal '<code class="role">foo bar baz</code>', para.content
+      end
+
       test 'should support attrlist on a literal monospace phrase' do
         input = '[.baz]`+foo--bar+`'
         para = block_from_string input