diff --git a/mozilla/layout/generic/nsLineLayout.h b/mozilla/layout/generic/nsLineLayout.h
index 1542bcd7dd5..308d0f6712b 100644
--- a/mozilla/layout/generic/nsLineLayout.h
+++ b/mozilla/layout/generic/nsLineLayout.h
@@ -59,6 +59,7 @@ public:
 
   void BeginLineReflow(nscoord aX, nscoord aY,
                        nscoord aWidth, nscoord aHeight,
+                       PRBool aImpactedByFloaters,
                        PRBool aIsTopOfPage);
 
   void EndLineReflow();
@@ -84,7 +85,6 @@ public:
                        nsIFrame** aNextRCFrame,
                        nsReflowStatus& aReflowStatus);
 
-
   nscoord GetCarriedOutTopMargin() const {
     return mCurrentSpan->mLastFrame->mCarriedOutTopMargin;
   }
@@ -146,6 +146,10 @@ public:
     return 0 == mTotalPlacedFrames;
   }
 
+  PRBool LineIsBreakable() const {
+    return (0 != mTotalPlacedFrames) || mImpactedByFloaters;
+  }
+
   //----------------------------------------
 
   // Inform the line-layout engine about the presence of a BR frame
@@ -229,6 +233,7 @@ protected:
   PRBool mWasInWord;
   PRBool mCanBreakBeforeFrame;
   PRBool mUpdatedBand;
+  PRBool mImpactedByFloaters;
   PRUint8 mPlacedFloaters;
   PRInt32 mTotalPlacedFrames;
   nsVoidArray mWordFrames;
diff --git a/mozilla/layout/html/base/src/nsLineLayout.h b/mozilla/layout/html/base/src/nsLineLayout.h
index 1542bcd7dd5..308d0f6712b 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.h
+++ b/mozilla/layout/html/base/src/nsLineLayout.h
@@ -59,6 +59,7 @@ public:
 
   void BeginLineReflow(nscoord aX, nscoord aY,
                        nscoord aWidth, nscoord aHeight,
+                       PRBool aImpactedByFloaters,
                        PRBool aIsTopOfPage);
 
   void EndLineReflow();
@@ -84,7 +85,6 @@ public:
                        nsIFrame** aNextRCFrame,
                        nsReflowStatus& aReflowStatus);
 
-
   nscoord GetCarriedOutTopMargin() const {
     return mCurrentSpan->mLastFrame->mCarriedOutTopMargin;
   }
@@ -146,6 +146,10 @@ public:
     return 0 == mTotalPlacedFrames;
   }
 
+  PRBool LineIsBreakable() const {
+    return (0 != mTotalPlacedFrames) || mImpactedByFloaters;
+  }
+
   //----------------------------------------
 
   // Inform the line-layout engine about the presence of a BR frame
@@ -229,6 +233,7 @@ protected:
   PRBool mWasInWord;
   PRBool mCanBreakBeforeFrame;
   PRBool mUpdatedBand;
+  PRBool mImpactedByFloaters;
   PRUint8 mPlacedFloaters;
   PRInt32 mTotalPlacedFrames;
   nsVoidArray mWordFrames;