Fix Assert failure for test case bug7714.html

Source/core/rendering/RenderTableSection.cpp

Index: Source/core/rendering/RenderTableSection.cpp
diff --git a/Source/core/rendering/RenderTableSection.cpp b/Source/core/rendering/RenderTableSection.cpp
index 282e7fa45ab0745dbbfa2c5ae61cf3c6524ae5f8..55e3d8601a2da227e0ae1539936e9eb2aeda338e 100644
--- a/Source/core/rendering/RenderTableSection.cpp
+++ b/Source/core/rendering/RenderTableSection.cpp
@@ -413,8 +413,16 @@ void RenderTableSection::distributeRowSpanHeightToRows(SpanningRenderTableCells&
 
         int originalBeforePosition = m_rowPos[rowIndex + rowSpan];
 
+        // When 2 spanning cells are ending at same row index then while extra height distribution of first spanning
+        // cell updates position of the last row so getting the original position of the last row in second spanning
+        // cell need to reduce the height changed by first spanning cell.
+        // In some cases, spanning cell's end row does not exit based on given rowspan value than in these cases, last
+        // row is consider as end row of the spanning cell.
+        if ((rowIndex + rowSpan) == (lastRowIndex + lastRowSpan) || ((rowIndex + rowSpan) >= (m_grid.size() + 1) && (lastRowIndex + lastRowSpan) >= (m_grid.size() + 1)))

[Julien - ping for review, 2013/08/07 16:51:30]

Do we really need to check if we have cells protuding out of the section?
RenderTableSection::addCell should make sure this never happens.

[a.suchit, 2013/08/07 19:49:50]

You are right that addCell will handle it.
I have done wrong here, This point did not come to me.
We need to check that next row is valid or not. Row is not valid means rows with
all invalid cells.
Here, I need to check that which is the last row is valid row in the table.

[a.suchit, 2013/08/08 11:17:40]

I checked it. What problem was in my mind that will not occur. Thanks

+            originalBeforePosition -= extraHeightToPropagate;
+
         if (extraHeightToPropagate) {
-            for (unsigned row = lastRowIndex + lastRowSpan; row <= rowIndex + rowSpan; row++)
+            for (unsigned row = lastRowIndex + lastRowSpan + 1; row <= rowIndex + rowSpan; row++)
                 m_rowPos[row] += extraHeightToPropagate;
         }
 
@@ -455,12 +463,11 @@ void RenderTableSection::distributeRowSpanHeightToRows(SpanningRenderTableCells&
 
         // Getting total changed height in the table
         extraHeightToPropagate = m_rowPos[rowIndex + rowSpan] - originalBeforePosition;
-        m_rowPos[rowIndex + rowSpan] -= extraHeightToPropagate;
     }
 
     if (extraHeightToPropagate) {
         // Apply changed height by rowSpan cells to rows present at the end of the table
-        for (unsigned row = lastRowIndex + lastRowSpan; row <= m_grid.size(); row++)
+        for (unsigned row = lastRowIndex + lastRowSpan + 1; row <= m_grid.size(); row++)
             m_rowPos[row] += extraHeightToPropagate;
     }
 }