Repeat footers in paginated context

third_party/WebKit/Source/core/paint/CollapsedBorderPainter.cpp

Index: third_party/WebKit/Source/core/paint/CollapsedBorderPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/CollapsedBorderPainter.cpp b/third_party/WebKit/Source/core/paint/CollapsedBorderPainter.cpp
index 86cbedac467d3876e45a4e55a82a2083a7c78ad3..ab88f536c7fc268f3651dd1f77ada5b6830bbdd3 100644
--- a/third_party/WebKit/Source/core/paint/CollapsedBorderPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/CollapsedBorderPainter.cpp
@@ -86,13 +86,19 @@ void CollapsedBorderPainter::SetupBorders() {
 
   // Skip painting the before border if it will be painted by the above cell
   // as its after border. If we break page before the row with non-zero strut
-  // (which means a gap between this row and the row above), we need to paint
-  // the before border separately.
+  // (which means a gap between this row and the row above), or if we are
+  // painting the top row of a footer that repeats on each page we need to paint
+  // the before border separately. This will double-paint the top border of the

[mstensho (USE GERRIT), 2017/07/17 10:38:08]

That double-painting doesn't seem like a good thing to do? Maybe add some paint
team reviewer.

[rhogan, 2017/07/24 18:56:07]

Will do. wangxianzhu would be ideal but he's off for a while. I think the double
painting is unavoidable for now due to the new way we paint collapsed borders.

[mstensho (USE GERRIT), 2017/07/25 08:59:32]

OK. A TODO, then.

+  // footer on the last page.
   if (before_.value && !cell_.Row()->PaginationStrut()) {
     const auto* cell_above = table_.CellAbove(cell_);
+    bool cell_is_top_of_repeating_footer =

[mstensho (USE GERRIT), 2017/07/17 10:38:08]

Sounds like a rare case, and a lot of other conditions need to be true before we
even need to evaluate this. Maybe move the check inside the following if-body.

[rhogan, 2017/07/24 18:56:07]

Done.

+        cell_.Section()->IsRepeatingFooterGroup() &&
+        (!cell_above || cell_above->Section() != cell_.Section());
     if (cell_.StartsAtSameColumn(cell_above) &&
         cell_above->ColSpan() >= cell_.ColSpan() &&
-        cell_above->Row()->HasSameDirectionAs(&table_)) {
+        cell_above->Row()->HasSameDirectionAs(&table_) &&
+        !cell_is_top_of_repeating_footer) {
       before_.value = nullptr;
       // Otherwise we'll still paint the shared border twice which may cause
       // incorrect border conflict resolution for row/col spanning cells.