Repeating header groups should align properly when captions are present

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/TableSectionPainter.h"
 
+#include "core/layout/LayoutTableCaption.h"
 #include "core/layout/LayoutTableCell.h"
 #include "core/layout/LayoutTableCol.h"
 #include "core/layout/LayoutTableRow.h"
 #include "core/paint/BoxClipper.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/ObjectPainter.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/TableCellPainter.h"
 #include "core/paint/TableRowPainter.h"
@@ skipping 47 matching lines @@
   // Now move paginationOffset to the top of the page the cull rect starts on.
   if (paintInfo.cullRect().m_rect.y() > paginationOffset.y())
     paginationOffset.move(
         0, pageHeight.toInt() *
                ((paintInfo.cullRect().m_rect.y() - paginationOffset.y()) /
                 pageHeight)
                    .toInt());
   LayoutUnit bottomBound =
       std::min(LayoutUnit(paintInfo.cullRect().m_rect.maxY()),
                paintOffset.y() + table->logicalHeight());
+  if (table->topCaption())
+    paginationOffset.move(0, -table->topCaption()->logicalHeight().toInt());

[mstensho (USE GERRIT), 2016/10/17 19:21:13]

So, it's possible to have as many top captions as you want, so this seems wrong.
How about subtracting the logical top of the section instead?

[rhogan, 2016/10/18 16:02:46]

Indeed, thanks - updated!

   while (paginationOffset.y() < bottomBound) {
     LayoutPoint nestedOffset =
         paginationOffset +
         LayoutPoint(0, m_layoutTableSection.offsetForRepeatingHeader().toInt());
     if (itemToPaint == PaintCollapsedBorders)
       paintCollapsedSectionBorders(paintInfo, nestedOffset, currentBorderValue);
     else
       paintSection(paintInfo, nestedOffset);
     paginationOffset.move(0, pageHeight.toInt());
   }
@@ skipping 306 matching lines @@
   LayoutRect bounds = BoxPainter(m_layoutTableSection)
                           .boundsForDrawingRecorder(paintInfo, paintOffset);
   LayoutObjectDrawingRecorder recorder(paintInfo.context, m_layoutTableSection,
                                        type, bounds);
   BoxPainter::paintBoxShadow(
       paintInfo, LayoutRect(paintOffset, m_layoutTableSection.size()),
       m_layoutTableSection.styleRef(), shadowStyle);
 }
 
 }  // namespace blink