1 files changed, 12 insertions, 14 deletions

diff --git a/layout/tables/nsTableRowFrame.cpp b/layout/tables/nsTableRowFrame.cpp
index 8bbaf50f5f..02b85a141f 100644
--- a/layout/tables/nsTableRowFrame.cpp
+++ b/layout/tables/nsTableRowFrame.cpp
@@ -235,7 +235,7 @@ nsTableRowFrame::InsertFrames(ChildListID  aListID,
   // insert the cells into the cell map
   int32_t colIndex = -1;
   if (prevCellFrame) {
-    prevCellFrame->GetColIndex(colIndex);
+    colIndex = prevCellFrame->ColIndex();
   }
   tableFrame->InsertCells(cellChildren, GetRowIndex(), colIndex);
 
@@ -647,8 +647,7 @@ CalcAvailISize(nsTableFrame&     aTableFrame,
                nsTableCellFrame& aCellFrame)
 {
   nscoord cellAvailISize = 0;
-  int32_t colIndex;
-  aCellFrame.GetColIndex(colIndex);
+  uint32_t colIndex = aCellFrame.ColIndex();
   int32_t colspan = aTableFrame.GetEffectiveColSpan(aCellFrame);
   NS_ASSERTION(colspan > 0, "effective colspan should be positive");
   nsTableFrame* fifTable =
@@ -787,12 +786,12 @@ nsTableRowFrame::ReflowChildren(nsPresContext*           aPresContext,
       }
     }
 
-    int32_t cellColIndex;
-    cellFrame->GetColIndex(cellColIndex);
+    uint32_t cellColIndex = cellFrame->ColIndex();
     cellColSpan = aTableFrame.GetEffectiveColSpan(*cellFrame);
 
     // If the adjacent cell is in a prior row (because of a rowspan) add in the space
-    if (prevColIndex != (cellColIndex - 1)) {
+    // NOTE: prevColIndex can be -1 here.
+    if (prevColIndex != (static_cast<int32_t>(cellColIndex) - 1)) {
       iCoord += GetSpaceBetween(prevColIndex, cellColIndex, cellColSpan, aTableFrame,
                                 false);
     }
@@ -1160,8 +1159,7 @@ nsTableRowFrame::CollapseRowIfNecessary(nscoord aRowOffset,
     shift = rowRect.BSize(wm);
     nsTableCellFrame* cellFrame = GetFirstCell();
     if (cellFrame) {
-      int32_t rowIndex;
-      cellFrame->GetRowIndex(rowIndex);
+      uint32_t rowIndex = cellFrame->RowIndex();
       shift += tableFrame->GetRowSpacing(rowIndex);
       while (cellFrame) {
         LogicalRect cRect = cellFrame->GetLogicalRect(wm, containerSize);
@@ -1192,13 +1190,13 @@ nsTableRowFrame::CollapseRowIfNecessary(nscoord aRowOffset,
     for (nsIFrame* kidFrame : mFrames) {
       nsTableCellFrame *cellFrame = do_QueryFrame(kidFrame);
       if (cellFrame) {
-        int32_t cellColIndex;
-        cellFrame->GetColIndex(cellColIndex);
+        uint32_t cellColIndex = cellFrame->ColIndex();
         int32_t cellColSpan = tableFrame->GetEffectiveColSpan(*cellFrame);
 
         // If the adjacent cell is in a prior row (because of a rowspan) add in
         // the space
-        if (prevColIndex != (cellColIndex - 1)) {
+        // NOTE: prevColIndex can be -1 here.
+        if (prevColIndex != (static_cast<int32_t>(cellColIndex) - 1)) {
           iPos += GetSpaceBetween(prevColIndex, cellColIndex, cellColSpan,
                                   *tableFrame, true);
         }
@@ -1311,9 +1309,9 @@ nsTableRowFrame::InsertCellFrame(nsTableCellFrame* aFrame,
   for (nsIFrame* child : mFrames) {
     nsTableCellFrame *cellFrame = do_QueryFrame(child);
     if (cellFrame) {
-      int32_t colIndex;
-      cellFrame->GetColIndex(colIndex);
-      if (colIndex < aColIndex) {
+      uint32_t colIndex = cellFrame->ColIndex();
+      // Can aColIndex be -1 here?  Let's assume it can for now.
+      if (static_cast<int32_t>(colIndex) < aColIndex) {
         priorCell = cellFrame;
       }
       else break;