Offset repeating theads correctly when two tables adjoin at a page border

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

Index: third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp b/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
index de99b1a78074181c0e748c1dce1a7146830b5ec2..877edf918a788bba14c3adf8266f24c98d5b3855 100644
--- a/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
@@ -45,7 +45,11 @@ void TableSectionPainter::paintRepeatingHeaderGroup(const PaintInfo& paintInfo,
     LayoutUnit pageHeight = table->pageLogicalHeightForOffset(LayoutUnit());
 
     // Move paginationOffset to the top of the next page.
-    LayoutUnit offsetToNextPage = pageHeight - intMod(table->pageLogicalOffset(), pageHeight);
+    // The header may have a pagination strut before it so we need to account for that when establishing its position.
+    LayoutUnit headerGroupOffset = table->pageLogicalOffset();
+    if (LayoutTableRow* row = m_layoutTableSection.firstRow())
+        headerGroupOffset += m_layoutTableSection.paginationStrutForRow(row, table->pageLogicalOffset());
+    LayoutUnit offsetToNextPage = pageHeight - intMod(headerGroupOffset, pageHeight);
     paginationOffset.move(0, offsetToNextPage);
     // Now move paginationOffset to the top of the page the cull rect starts on.
     if (paintInfo.cullRect().m_rect.y() > paginationOffset.y())