resolves #1533 place dots on correct page when section title in TOC wraps across page boundary

CHANGELOG.adoc

@@ -12,6 +12,7 @@ For a detailed view of what has changed, refer to the {uri-repo}/commits/master[
 * allow font path to be declared once for all font styles (#1507)
 * continue border, background, and column rule of admonition block on subsequent pages when block gets split (#1287)
 * allow max-width on caption be specified as a percentage (of the container width) (#1484)
+* place dots on correct page when section title in TOC wraps across a page boundary (#1533)
 * add destination to top of imported PDF if ID is specified on image block
 * log reason if theme file cannot be parsed or compiled (#1491)
 * bundle emoji font and use as fallback in default-with-fallback-font theme (#1129)

lib/asciidoctor/pdf/converter.rb

@@ -3027,7 +3027,11 @@ def layout_toc_level sections, num_levels, line_metrics, dot_leader, num_front_m
                 start_dots = last_fragment_pos.right + hanging_indent
                 last_fragment_cursor = last_fragment_pos.top + line_metrics.padding_top
                 # NOTE this will be incorrect if wrapped line is all monospace
-                start_cursor = last_fragment_cursor if start_cursor - last_fragment_cursor > line_metrics.height
+                if (last_fragment_page_number = last_fragment_pos.page_number) > start_page_number ||
+                    (start_cursor - last_fragment_cursor) > line_metrics.height
+                  start_page_number = last_fragment_page_number
+                  start_cursor = last_fragment_cursor
+                end
               end
               end_page_number = page_number
               end_cursor = cursor

lib/asciidoctor/pdf/formatted_text/fragment_position_renderer.rb

@@ -2,12 +2,13 @@
 
 module Asciidoctor::PDF::FormattedText
   class FragmentPositionRenderer
-    attr_reader :top, :right, :bottom, :left
+    attr_reader :top, :right, :bottom, :left, :page_number
 
     def render_behind fragment
       @top = fragment.top
       @right = (@left = fragment.left) + fragment.width
       @bottom = fragment.bottom
+      @page_number = fragment.document.page_number
     end
   end
 end

spec/toc_spec.rb

@@ -311,6 +311,26 @@
       (expect page_number_text).to have_size 1
     end
 
+    it 'should line up dots and page number with wrapped line when section title gets split across a page boundary' do
+      sections = (1..37).map {|num| %(\n\n== Section #{num}) }.join
+      pdf = to_pdf <<~EOS, doctype: :book, analyze: true
+      = Document Title
+      :toc:
+      #{sections}
+
+      == This is a unbelievably long section title that probably shouldn't be a section title at all but here we are
+
+      content
+      EOS
+
+      page_2_lines = pdf.lines pdf.find_text page_number: 2
+      (expect page_2_lines).to include 'Table of Contents'
+      (expect page_2_lines[-1]).to end_with 'but here'
+      page_3_lines = pdf.lines pdf.find_text page_number: 3
+      (expect page_3_lines).to have_size 1
+      (expect page_3_lines[0]).to match %r/we are(\. )+.*38$/
+    end
+
     it 'should allow hanging indent to be applied to lines that wrap' do
       pdf = to_pdf <<~'EOS', doctype: :book, pdf_theme: { toc_hanging_indent: 36 }, analyze: true
       = Document Title