diff --git a/mozilla/layout/generic/nsInlineFrame.cpp b/mozilla/layout/generic/nsInlineFrame.cpp
index 68f2d0df7af..cde40c4fe09 100644
--- a/mozilla/layout/generic/nsInlineFrame.cpp
+++ b/mozilla/layout/generic/nsInlineFrame.cpp
@@ -258,6 +258,23 @@ nsInlineFrame::FindTextRuns(nsLineLayout&  aLineLayout,
   return rv;
 }
 
+void
+nsInlineFrame::InsertNewFrame(nsIFrame* aNewFrame, nsIFrame* aPrevSibling)
+{
+  nsIFrame* nextSibling = nsnull;
+
+  if (nsnull == aPrevSibling) {
+    if (nsnull != mFirstChild) {
+      mFirstChild->GetNextSibling(nextSibling);
+    }
+    mFirstChild = aNewFrame;
+  } else {
+    aPrevSibling->GetNextSibling(nextSibling);
+    aPrevSibling->SetNextSibling(aNewFrame);
+  }
+  aNewFrame->SetNextSibling(nextSibling);
+}
+
 NS_IMETHODIMP
 nsInlineFrame::InlineReflow(nsLineLayout&     aLineLayout,
                                nsReflowMetrics&     aMetrics,
@@ -300,11 +317,20 @@ nsInlineFrame::InlineReflow(nsLineLayout&     aLineLayout,
     if (this == target) {
       nsIReflowCommand::ReflowType type;
       state.reflowCommand->GetType(type);
+      nsIFrame* newFrame;
+      nsIFrame* prevSibling;
       switch (type) {
       case nsIReflowCommand::FrameAppended:
         rv = FrameAppendedReflow(state);
         break;
 
+      case nsIReflowCommand::FrameInserted:
+        // Link the new frame into the child list
+        state.reflowCommand->GetChildFrame(newFrame);
+        state.reflowCommand->GetPrevSiblingFrame(prevSibling);
+        InsertNewFrame(newFrame, prevSibling);
+        // fall thru...
+
       default:
         // XXX For now map the other incremental operations into full reflows
         rv = ResizeReflow(state);
diff --git a/mozilla/layout/html/base/src/deadnsInlineFrame.h b/mozilla/layout/html/base/src/deadnsInlineFrame.h
index 3ad085d4575..0967e475659 100644
--- a/mozilla/layout/html/base/src/deadnsInlineFrame.h
+++ b/mozilla/layout/html/base/src/deadnsInlineFrame.h
@@ -122,6 +122,8 @@ protected:
 
   nsresult AppendNewFrames(nsIPresContext* aPresContext, nsIFrame*);
 
+  void InsertNewFrame(nsIFrame* aNewFrame, nsIFrame* aPrevSibling);
+
   friend nsresult NS_NewInlineFrame(nsIContent* aContent, nsIFrame* aParentFrame,
                                     nsIFrame*& aNewFrame);
 };
diff --git a/mozilla/layout/html/base/src/nsInlineFrame.cpp b/mozilla/layout/html/base/src/nsInlineFrame.cpp
index 68f2d0df7af..cde40c4fe09 100644
--- a/mozilla/layout/html/base/src/nsInlineFrame.cpp
+++ b/mozilla/layout/html/base/src/nsInlineFrame.cpp
@@ -258,6 +258,23 @@ nsInlineFrame::FindTextRuns(nsLineLayout&  aLineLayout,
   return rv;
 }
 
+void
+nsInlineFrame::InsertNewFrame(nsIFrame* aNewFrame, nsIFrame* aPrevSibling)
+{
+  nsIFrame* nextSibling = nsnull;
+
+  if (nsnull == aPrevSibling) {
+    if (nsnull != mFirstChild) {
+      mFirstChild->GetNextSibling(nextSibling);
+    }
+    mFirstChild = aNewFrame;
+  } else {
+    aPrevSibling->GetNextSibling(nextSibling);
+    aPrevSibling->SetNextSibling(aNewFrame);
+  }
+  aNewFrame->SetNextSibling(nextSibling);
+}
+
 NS_IMETHODIMP
 nsInlineFrame::InlineReflow(nsLineLayout&     aLineLayout,
                                nsReflowMetrics&     aMetrics,
@@ -300,11 +317,20 @@ nsInlineFrame::InlineReflow(nsLineLayout&     aLineLayout,
     if (this == target) {
       nsIReflowCommand::ReflowType type;
       state.reflowCommand->GetType(type);
+      nsIFrame* newFrame;
+      nsIFrame* prevSibling;
       switch (type) {
       case nsIReflowCommand::FrameAppended:
         rv = FrameAppendedReflow(state);
         break;
 
+      case nsIReflowCommand::FrameInserted:
+        // Link the new frame into the child list
+        state.reflowCommand->GetChildFrame(newFrame);
+        state.reflowCommand->GetPrevSiblingFrame(prevSibling);
+        InsertNewFrame(newFrame, prevSibling);
+        // fall thru...
+
       default:
         // XXX For now map the other incremental operations into full reflows
         rv = ResizeReflow(state);