backport fix for #3583 preserve repeating spaces in verbatim content in manpage output

3 files changed, 34 insertions, 2 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 59f85aa0..cfdabf47 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -33,6 +33,7 @@ Bug Fixes::
   * Don't crash when parsing xref shorthand if target starts with URL protocol and text is offset by space (#4570)
   * Only drop current row if colspan of last cell exceeds specified number of columns (#4587)
   * Drop last row if colspan of last cell in table exceeds specified number of columns (#4587)
+  * Preserve repeating spaces in verbatim content in manpage output (#3583)
 
 == 2.0.22 (2024-03-08) - @mojavelinux
 
diff --git a/lib/asciidoctor/converter/manpage.rb b/lib/asciidoctor/converter/manpage.rb
index 726d187c..398192fa 100644
--- a/lib/asciidoctor/converter/manpage.rb
+++ b/lib/asciidoctor/converter/manpage.rb
@@ -699,7 +699,7 @@ allbox tab(:);'
   def manify str, opts = {}
     case opts.fetch :whitespace, :collapse
     when :preserve
-      str = str.gsub TAB, ET
+      str = (str.gsub TAB, ET).gsub(/(^)?  +/) { $1 ? $& : %(#{ESC_BS}&#{$&}) }
     when :normalize
       str = str.gsub WrappedIndentRx, LF
     else
diff --git a/test/manpage_test.rb b/test/manpage_test.rb
index db4cf8f4..5e0bbd80 100644
--- a/test/manpage_test.rb
+++ b/test/manpage_test.rb
@@ -348,6 +348,37 @@ context 'Manpage' do
       assert_includes output, %(Oh, here it goes again\nI should have known,\nshould have known,\nshould have known again)
     end
 
+    test 'should escape repeated spaces in literal content' do
+      input = <<~EOS.chop
+      #{SAMPLE_MANPAGE_HEADER}
+
+      ....
+        ,---.          ,-----.
+        |Bob|          |Alice|
+        `-+-'          `--+--'
+          |    hello      |
+          |-------------->|
+        ,-+-.          ,--+--.
+        |Bob|          |Alice|
+        `---'          `-----'
+      ....
+      EOS
+
+      output = Asciidoctor.convert input, backend: :manpage
+      assert_includes output, <<~'EOS'
+      .fam C
+        ,\-\-\-.\&          ,\-\-\-\-\-.
+        |Bob|\&          |Alice|
+        `\-+\-\*(Aq\&          `\-\-+\-\-\*(Aq
+          |\&    hello\&      |
+          |\-\-\-\-\-\-\-\-\-\-\-\-\-\->|
+        ,\-+\-.\&          ,\-\-+\-\-.
+        |Bob|\&          |Alice|
+        `\-\-\-\*(Aq\&          `\-\-\-\-\-\*(Aq
+      .fam
+      EOS
+    end
+
     test 'should preserve break between paragraphs in normal table cell' do
       input = <<~EOS.chop
       #{SAMPLE_MANPAGE_HEADER}
@@ -818,7 +849,7 @@ context 'Manpage' do
       .sp
       .nf
       b
-      c    _d_
+      c\&    _d_
       \&.
       .fi
       T}