resolves asciidoctor#2487 fix page number of index entries in prepres…

…s book when page numbering starts after toc and toc is inserted using macro

CHANGELOG.adoc

@@ -52,6 +52,7 @@ Bug Fixes::
 * don't crash if page background image value is empty (interpret as "none")
 * prevent special character substitution from interfering with callouts in plain verbatim block (#2390)
 * remove deprecated, undocumented `svg-font-family` theme key (the correct key is `svg-fallback-font-family`)
+* fix page number of index entries in prepress book when page numbering starts after toc and toc is inserted using macro (#2487)
 
 == 2.3.11 (2024-01-23) - @mojavelinux
 

lib/asciidoctor/pdf/converter.rb

@@ -2385,7 +2385,11 @@ def convert_toc node, opts = {}
           start_toc_page node, placement if (is_book = doc.doctype == 'book')
           add_dest_for_block node, id: (node.id || 'toc') if is_macro
           toc_extent = @toc_extent = allocate_toc doc, (doc.attr 'toclevels', 2).to_i, cursor, (title_page_on = is_book || (doc.attr? 'title-page'))
-          @index.start_page_number = toc_extent.to.page + 1 if title_page_on && @theme.page_numbering_start_at == 'after-toc'
+          if title_page_on && @theme.page_numbering_start_at == 'after-toc'
+            new_start_page_number = toc_extent.to.page + 1
+            new_start_page_number += 1 if @ppbook && (verso_page? new_start_page_number)
+            @index.start_page_number = new_start_page_number
+          end
           if is_macro
             @disable_running_content[:header] += toc_extent.page_range if node.option? 'noheader'
             @disable_running_content[:footer] += toc_extent.page_range if node.option? 'nofooter'

spec/index_spec.rb

@@ -525,6 +525,33 @@
     (expect terms).to eql %w(anchor AsciiDoc Asciidoctor authoring)
   end
 
+  it 'should adjust start page number for prepress book when page numbering starts after-toc and toc macro is used' do
+    pdf = to_pdf <<~'END', pdf_theme: { page_numbering_start_at: 'after-toc' }, analyze: true
+    = Book Title
+    :doctype: book
+    :media: prepress
+    :toc: macro
+
+    toc::[]
+
+    == First Chapter
+
+    ((apples))
+
+    == Second Chapter
+
+    ((bananas))
+
+    [index]
+    == Index
+    END
+
+    index_title_text = (pdf.find_text 'Index')[-1]
+    (expect index_title_text[:page_number]).to be 9
+    index_lines = pdf.lines pdf.find_text page_number: 9
+    (expect index_lines).to eql ['Index', 'A', 'apples, 1', 'B', 'bananas, 3']
+  end
+
   it 'should start with no categories' do
     index = Asciidoctor::PDF::IndexCatalog.new
     (expect index).to be_empty