don't push section that follows index section in article to new page if last page of index does not extend to bottom of page

3 files changed, 68 insertions, 0 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index a73be1d1..a18242e7 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -15,6 +15,7 @@ Bug Fixes::
 * `at_page_top?` should consider top of column box to be top of page
 * prevent SVG image taller than column from being advanced to next column
 * fix computation of default height for formatted box inside column box
+* don't push section that follows index section in article to new page if last page of index does not extend to bottom of page
 
 == 2.0.7 (2022-06-03) - @mojavelinux
 
diff --git a/lib/asciidoctor/pdf/converter.rb b/lib/asciidoctor/pdf/converter.rb
index e9a0c57f..c969484c 100644
--- a/lib/asciidoctor/pdf/converter.rb
+++ b/lib/asciidoctor/pdf/converter.rb
@@ -702,6 +702,7 @@ module Asciidoctor
       def convert_index_section node
         space_needed_for_category = @theme.description_list_term_spacing + (2 * (height_of_typeset_text 'A'))
         pagenum_sequence_style = node.document.attr 'index-pagenum-sequence-style'
+        end_cursor = nil
         column_box [0, cursor], columns: @theme.index_columns, width: bounds.width, reflow_margins: true, spacer: @theme.index_column_gap do
           @index.categories.each do |category|
             bounds.move_past_bottom if space_needed_for_category > cursor
@@ -713,7 +714,10 @@ module Asciidoctor
             category.terms.each {|term| convert_index_list_item term, pagenum_sequence_style }
             @theme.prose_margin_bottom > cursor ? bounds.move_past_bottom : (move_down @theme.prose_margin_bottom)
           end
+          end_cursor = cursor if (bounds.instance_variable_get :@current_column) == 0
         end
+        # Q: could we move this logic into column_box?
+        move_cursor_to end_cursor if end_cursor
         nil
       end
 
diff --git a/spec/index_spec.rb b/spec/index_spec.rb
index 0fe4bd6c..5069bea9 100644
--- a/spec/index_spec.rb
+++ b/spec/index_spec.rb
@@ -870,4 +870,67 @@ describe 'Asciidoctor::PDF::Converter - Index' do
     chapter_a_toc_text = pdf.find_unique_text 'Chapter A', page_number: 2
     (expect chapter_a_toc_text[:x]).to eql 98.24
   end
+
+  it 'should not push following section to new page if index section does not extend to bottom of page' do
+    pdf = to_pdf <<~'EOS', analyze: true
+    = Document Title
+
+    == Chapter About Cats
+
+    We know that ((cats)) control the internet.
+    But they sort of run nature too.
+    (((cats,big cats,lion)))
+    After all, the ((king of the jungle)) is the lion, which is a big cat.
+
+    == Chapter About Dogs
+
+    Cats may rule, well, everything.
+    But ((dogs)) are a human's best friend.
+
+    [index]
+    == Index
+
+    == Section After Index
+    EOS
+
+    (expect pdf.pages).to have_size 1
+    category_k_text = pdf.find_unique_text 'K'
+    (expect category_k_text[:page_number]).to eql 1
+    section_after_index_text = pdf.find_unique_text 'Section After Index'
+    (expect section_after_index_text[:page_number]).to eql 1
+    (expect section_after_index_text[:y]).to be < category_k_text[:y]
+  end
+
+  it 'should not push following section to new page if index section does not extend to bottom of second page' do
+    pdf = to_pdf <<~EOS, analyze: true, debug: true
+    = Document Title
+
+    #{('a'..'z').map {|it| %(((#{it}-term))) }.join}
+
+    == Chapter About Cats
+
+    We know that ((cats)) control the internet.
+    But they sort of run nature too.
+    (((cats,big cats,lion)))
+    After all, the ((king of the jungle)) is the lion, which is a big cat.
+
+    == Chapter About Dogs
+
+    Cats may rule, well, everything.
+    But ((dogs)) are a human's best friend.
+
+    [index]
+    == Index
+
+    == Section After Index
+    EOS
+
+    (expect pdf.pages).to have_size 2
+    category_z_text = pdf.find_unique_text 'Z'
+    (expect category_z_text[:page_number]).to eql 2
+    (expect category_z_text[:x]).to eql 48.24
+    section_after_index_text = pdf.find_unique_text 'Section After Index'
+    (expect section_after_index_text[:page_number]).to eql 2
+    (expect section_after_index_text[:y]).to be < category_z_text[:y]
+  end
 end