Repeat footers in paginated context

third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1121 matching lines @@
   line_box.SetIsFirstAfterPageBreak(false);
   LayoutState* layout_state = View()->GetLayoutState();
   if (!layout_state->IsPaginated())
     return;
   if (!IsPageLogicalHeightKnown())
     return;
   LayoutUnit page_logical_height = PageLogicalHeightForOffset(logical_offset);
   LayoutUnit remaining_logical_height = PageRemainingLogicalHeightForOffset(
       logical_offset, kAssociateWithLatterPage);
   int line_index = LineCount(&line_box);
-  if (remaining_logical_height < line_height ||
+  // We need to detect if we overlap a repeating footer and if so take the
+  // full remaining logical height as our strut to the next page.

[mstensho (USE GERRIT), 2017/06/20 21:39:05]

But why wouldn't you want to do the same for other types of content that we
don't want to break inside? Why is it limited to lines? What about blocks with
break-inside:avoid? They should also steer clear of repeatables, no?

+  LayoutUnit remaining_logical_height_including_footer =
+      remaining_logical_height - layout_state->HeightOffsetForTableFooters();
+  if (remaining_logical_height_including_footer < line_height ||
       (ShouldBreakAtLineToAvoidWidow() &&
        LineBreakToAvoidWidow() == line_index)) {
     LayoutUnit pagination_strut = CalculatePaginationStrutToFitContent(
         logical_offset, remaining_logical_height, line_height);
     LayoutUnit new_logical_offset = logical_offset + pagination_strut;
     // Moving to a different page or column may mean that its height is
     // different.
     page_logical_height = PageLogicalHeightForOffset(new_logical_offset);
     if (line_height > page_logical_height) {
       // Too tall to fit in one page / column. Give up. Don't push to the next
@@ skipping 3606 matching lines @@
   return LayoutBlock::DeprecatedInvalidatePaint(paint_invalidation_state);
 }
 
 void LayoutBlockFlow::InvalidateDisplayItemClients(
     PaintInvalidationReason invalidation_reason) const {
   BlockFlowPaintInvalidator(*this).InvalidateDisplayItemClients(
       invalidation_reason);
 }
 
 }  // namespace blink