don't allow target of include directive to start or end with a space

CHANGELOG.adoc

@@ -31,6 +31,7 @@ Compliance::
 Bug Fixes::
 
   * Use correct selector to collapse margin on first and last child of sidebar
+  * Don't allow target of include directive to start with a space (to distinguish it from a dlist item) or to end with a space
 
 == 2.0.18 (2022-10-15) - @mojavelinux
 

lib/asciidoctor/rx.rb

@@ -89,7 +89,7 @@ module Rx; end
   #   include::chapter1.ad[]
   #   include::example.txt[lines=1;2;5..10]
   #
-  IncludeDirectiveRx = /^(\\)?include::([^\[][^\[]*)\[(#{CC_ANY}+)?\]$/
+  IncludeDirectiveRx = /^(\\)?include::([^\s\[](?:[^\[]*[^\s\[])?)\[(#{CC_ANY}+)?\]$/
 
   # Matches a trailing tag directive in an include file.
   #

test/lists_test.rb

@@ -2128,6 +2128,22 @@
       assert_css 'dl > dt:empty', output, 1
     end
 
+    test 'should parse a dlist if term is include and principal text is []' do
+      input = 'include:: []'
+      output = convert_string_to_embedded input
+      assert_css 'dl', output, 1
+      assert_css 'dl > dt', output, 1
+      assert_xpath '(//dl/dt)[1]/following-sibling::dd/p[text() = "[]"]', output, 1
+    end
+
+    test 'should parse a dlist if term is include and principal text matches macro form' do
+      input = 'include:: pass:[${placeholder}]'
+      output = convert_string_to_embedded input
+      assert_css 'dl', output, 1
+      assert_css 'dl > dt', output, 1
+      assert_xpath '(//dl/dt)[1]/following-sibling::dd/p[text() = "${placeholder}"]', output, 1
+    end
+
     test "single-line adjacent elements" do
       input = <<~'EOS'
       term1:: def1

test/reader_test.rb

@@ -713,6 +713,14 @@ class ReaderTest < Minitest::Test
         end
       end
 
+      test 'include directive should not match if target is empty or starts or ends with space' do
+        ['include::[]', 'include:: []', 'include:: not-include[]', 'include::not-include []'].each do |input|
+          doc = Asciidoctor::Document.new input
+          reader = doc.reader
+          assert_equal input, reader.read_line
+        end
+      end
+
       test 'include directive should not attempt to resolve target as remote if allow-uri-read is set and URL is not on first line' do
         using_memory_logger do |logger|
           input = <<~'EOS'