diff --git a/mozilla/layout/generic/nsBlockFrame.cpp b/mozilla/layout/generic/nsBlockFrame.cpp
index c50305ea44f..91c1ec4c672 100644
--- a/mozilla/layout/generic/nsBlockFrame.cpp
+++ b/mozilla/layout/generic/nsBlockFrame.cpp
@@ -3822,7 +3822,12 @@ nsBlockFrame::SplitLine(nsBlockReflowState& aState,
   if (gNoisyReflow) {
     nsFrame::IndentBy(stdout, gNoiseIndent);
     printf("split line: from line=%p pushCount=%d aFrame=", aLine, pushCount);
-    nsFrame::ListTag(stdout, aFrame);
+    if (aFrame) {
+      nsFrame::ListTag(stdout, aFrame);
+    }
+    else {
+      printf("(null)");
+    }
     printf("\n");
     if (gReallyNoisyReflow) {
       aLine->List(aState.mPresContext, stdout, gNoiseIndent+1);
diff --git a/mozilla/layout/generic/nsBlockReflowState.cpp b/mozilla/layout/generic/nsBlockReflowState.cpp
index c50305ea44f..91c1ec4c672 100644
--- a/mozilla/layout/generic/nsBlockReflowState.cpp
+++ b/mozilla/layout/generic/nsBlockReflowState.cpp
@@ -3822,7 +3822,12 @@ nsBlockFrame::SplitLine(nsBlockReflowState& aState,
   if (gNoisyReflow) {
     nsFrame::IndentBy(stdout, gNoiseIndent);
     printf("split line: from line=%p pushCount=%d aFrame=", aLine, pushCount);
-    nsFrame::ListTag(stdout, aFrame);
+    if (aFrame) {
+      nsFrame::ListTag(stdout, aFrame);
+    }
+    else {
+      printf("(null)");
+    }
     printf("\n");
     if (gReallyNoisyReflow) {
       aLine->List(aState.mPresContext, stdout, gNoiseIndent+1);
diff --git a/mozilla/layout/generic/nsBlockReflowState.h b/mozilla/layout/generic/nsBlockReflowState.h
index c50305ea44f..91c1ec4c672 100644
--- a/mozilla/layout/generic/nsBlockReflowState.h
+++ b/mozilla/layout/generic/nsBlockReflowState.h
@@ -3822,7 +3822,12 @@ nsBlockFrame::SplitLine(nsBlockReflowState& aState,
   if (gNoisyReflow) {
     nsFrame::IndentBy(stdout, gNoiseIndent);
     printf("split line: from line=%p pushCount=%d aFrame=", aLine, pushCount);
-    nsFrame::ListTag(stdout, aFrame);
+    if (aFrame) {
+      nsFrame::ListTag(stdout, aFrame);
+    }
+    else {
+      printf("(null)");
+    }
     printf("\n");
     if (gReallyNoisyReflow) {
       aLine->List(aState.mPresContext, stdout, gNoiseIndent+1);
diff --git a/mozilla/layout/generic/nsLineLayout.cpp b/mozilla/layout/generic/nsLineLayout.cpp
index d42550ec4e8..e5a75118813 100644
--- a/mozilla/layout/generic/nsLineLayout.cpp
+++ b/mozilla/layout/generic/nsLineLayout.cpp
@@ -113,6 +113,7 @@ nsLineLayout::nsLineLayout(nsIPresContext& aPresContext,
   mColumn = 0;
   mEndsInWhiteSpace = PR_TRUE;
   mUnderstandsWhiteSpace = PR_FALSE;
+  mTextStartsWithNBSP = PR_FALSE;
   mFirstLetterStyleOK = PR_FALSE;
   mIsTopOfPage = PR_FALSE;
   mUpdatedBand = PR_FALSE;
@@ -270,6 +271,7 @@ nsLineLayout::BeginLineReflow(nscoord aX, nscoord aY,
   mColumn = 0;
   mEndsInWhiteSpace = PR_TRUE;
   mUnderstandsWhiteSpace = PR_FALSE;
+  mTextStartsWithNBSP = PR_FALSE;
   mFirstLetterStyleOK = PR_FALSE;
   mIsTopOfPage = aIsTopOfPage;
   mUpdatedBand = PR_FALSE;
@@ -411,6 +413,7 @@ nsLineLayout::UpdateBand(nscoord aX, nscoord aY,
   mLastFloaterWasLetterFrame = nsLayoutAtoms::letterFrame == frameType.get();
 
   // Now update all of the open spans...
+  mRootSpan->mContainsFloater = PR_TRUE;              // make sure mRootSpan gets updated too
   psd = mCurrentSpan;
   while (psd != mRootSpan) {
     NS_ASSERTION(nsnull != psd, "null ptr");
@@ -424,6 +427,7 @@ nsLineLayout::UpdateBand(nscoord aX, nscoord aY,
     else {
       psd->mRightEdge += deltaWidth;
     }
+    psd->mContainsFloater = PR_TRUE;
 #ifdef NOISY_REFLOW
     printf("  span %p: oldRightEdge=%d newRightEdge=%d\n",
            psd, psd->mRightEdge - deltaWidth, psd->mRightEdge);
@@ -479,6 +483,8 @@ nsLineLayout::NewPerSpanData(PerSpanData** aResult)
   psd->mFrame = nsnull;
   psd->mFirstFrame = nsnull;
   psd->mLastFrame = nsnull;
+  psd->mContainsFloater = PR_FALSE;
+  psd->mZeroEffectiveSpanBox = PR_FALSE;
 
 #ifdef DEBUG
   mSpansAllocated++;
@@ -514,7 +520,6 @@ nsLineLayout::BeginSpan(nsIFrame* aFrame,
     psd->mLeftEdge = aLeftEdge;
     psd->mX = aLeftEdge;
     psd->mRightEdge = aRightEdge;
-    psd->mZeroEffectiveSpanBox = PR_FALSE;
 
     const nsStyleText* styleText;
     aSpanReflowState->frame->GetStyleData(eStyleStruct_Text,
@@ -879,6 +884,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
   reflowState.mLineLayout = this;
   reflowState.isTopOfPage = mIsTopOfPage;
   mUnderstandsWhiteSpace = PR_FALSE;
+  mTextStartsWithNBSP = PR_FALSE;
 
   // Stash copies of some of the computed state away for later
   // (vertical alignment, for example)
@@ -1095,8 +1101,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
 
     // See if we can place the frame. If we can't fit it, then we
     // return now.
-    if (CanPlaceFrame(pfd, reflowState, notSafeToBreak, metrics,
-                      aReflowStatus)) {
+    if (CanPlaceFrame(pfd, reflowState, notSafeToBreak, metrics, aReflowStatus)) {
       // Place the frame, updating aBounds with the final size and
       // location.  Then apply the bottom+right margins (as
       // appropriate) to the frame.
@@ -1116,6 +1121,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
   else {
     PushFrame(aFrame);
   }
+  mTextStartsWithNBSP = PR_FALSE;           // reset for next time
 
 #ifdef REALLY_NOISY_REFLOW
   nsFrame::IndentBy(stdout, mSpanDepth);
@@ -1234,7 +1240,7 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
 
   PerSpanData* psd = mCurrentSpan;
   if (psd->mNoWrap) {
-    // When wrapping is off, everything fits
+    // When wrapping is off, everything fits.
     return PR_TRUE;
   }
 
@@ -1345,6 +1351,43 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
     }
   }
 
+  // Special check for span frames
+  if (pfd->mSpan && pfd->mSpan->mContainsFloater) {
+    // If the span either directly or indirectly contains a floater then
+    // it fits. Why? It's kind of complicated, but here goes:
+    //
+    // 1. CanPlaceFrame is used for all frame placements on a line,
+    // and in a span. This includes recursively placement of frames
+    // inside of spans, and the span itself. Because the logic always
+    // checks for room before proceeding (the code above here), the
+    // only things on a line will be those things that "fit".
+    //
+    // 2. Before a floater is placed on a line, the line has to be empty
+    // (otherwise its a "below current line" flaoter and will be placed
+    // after the line).
+    //
+    // Therefore, if the span directly or indirectly has a floater
+    // then it means that at the time of the placement of the floater
+    // the line was empty. Because of #1, only the frames that fit can
+    // be added after that point, therefore we can assume that the
+    // current span being placed has fit.
+    //
+    // So how do we get here and have a span that should already fit
+    // and yet doesn't: Simple: span's that have the no-wrap attribute
+    // set on them and contain a floater and are placed where they
+    // don't naturally fit.
+    return PR_TRUE;
+ }
+
+  // Yet another special check. If the text happens to have started
+  // with a non-breaking space, then we make it sticky on its left
+  // edge...Which means that whatever piece of text we just formatted
+  // will be the piece that fits (the text frame logic knows to stop
+  // when it runs out of room).
+  if (pfd->mIsNonEmptyTextFrame && mTextStartsWithNBSP) {
+    return PR_TRUE;
+  }
+
 #ifdef NOISY_CAN_PLACE_FRAME
   printf("   ==> didn't fit\n");
 #endif
diff --git a/mozilla/layout/generic/nsLineLayout.h b/mozilla/layout/generic/nsLineLayout.h
index 7426f332de6..e12a094363b 100644
--- a/mozilla/layout/generic/nsLineLayout.h
+++ b/mozilla/layout/generic/nsLineLayout.h
@@ -128,6 +128,10 @@ public:
     mUnderstandsWhiteSpace = aSetting;
   }
 
+  void SetTextStartsWithNBSP(PRBool aYes) {
+    mTextStartsWithNBSP = aYes;
+  }
+
   void RecordWordFrame(nsIFrame* aWordFrame) {
     mWordFrames.AppendElement(aWordFrame);
   }
@@ -222,6 +226,7 @@ protected:
   PRInt32 mColumn;
   PRBool mEndsInWhiteSpace;
   PRBool mUnderstandsWhiteSpace;
+  PRBool mTextStartsWithNBSP;
   PRBool mFirstLetterStyleOK;
   PRBool mIsTopOfPage;
   PRBool mUpdatedBand;
@@ -317,6 +322,7 @@ public:
     PRUint8 mDirection;
     PRBool mChangedFrameDirection;
     PRBool mZeroEffectiveSpanBox;
+    PRBool mContainsFloater;
 
     nscoord mLeftEdge;
     nscoord mX;
diff --git a/mozilla/layout/generic/nsTextFrame.cpp b/mozilla/layout/generic/nsTextFrame.cpp
index f354552c77e..771daf6404d 100644
--- a/mozilla/layout/generic/nsTextFrame.cpp
+++ b/mozilla/layout/generic/nsTextFrame.cpp
@@ -2818,6 +2818,8 @@ nsTextFrame::Reflow(nsIPresContext& aPresContext,
     }
   }
 
+  PRBool firstThing = PR_TRUE;
+  PRBool textStartsWithNBSP = PR_FALSE;
   for (;;) {
     // Get next word/whitespace from the text
     PRBool isWhitespace;
@@ -2886,8 +2888,16 @@ nsTextFrame::Reflow(nsIPresContext& aPresContext,
         }
         lastWordWidth = width;
       }
+
+      // See if the first thing in the section of text is a
+      // non-breaking space (html nbsp entity). If it is then make
+      // note of that fact for the line layout logic.
+      if (wrapping && firstThing && (bp[0] == ' ')) {
+        textStartsWithNBSP = PR_TRUE;
+      }
       skipWhitespace = PR_FALSE;
     }
+    firstThing = PR_FALSE;
 
     // See if there is room for the text
     if (measureText) {
@@ -3050,6 +3060,7 @@ nsTextFrame::Reflow(nsIPresContext& aPresContext,
   // text object collapsed into nothingness which means it shouldn't
   // effect the current setting of the ends-in-whitespace flag.
   lineLayout.SetUnderstandsWhiteSpace(PR_TRUE);
+  lineLayout.SetTextStartsWithNBSP(textStartsWithNBSP);
   if (0 != x) {
     lineLayout.SetEndsInWhiteSpace(endsInWhitespace);
   }
diff --git a/mozilla/layout/html/base/src/nsBlockFrame.cpp b/mozilla/layout/html/base/src/nsBlockFrame.cpp
index c50305ea44f..91c1ec4c672 100644
--- a/mozilla/layout/html/base/src/nsBlockFrame.cpp
+++ b/mozilla/layout/html/base/src/nsBlockFrame.cpp
@@ -3822,7 +3822,12 @@ nsBlockFrame::SplitLine(nsBlockReflowState& aState,
   if (gNoisyReflow) {
     nsFrame::IndentBy(stdout, gNoiseIndent);
     printf("split line: from line=%p pushCount=%d aFrame=", aLine, pushCount);
-    nsFrame::ListTag(stdout, aFrame);
+    if (aFrame) {
+      nsFrame::ListTag(stdout, aFrame);
+    }
+    else {
+      printf("(null)");
+    }
     printf("\n");
     if (gReallyNoisyReflow) {
       aLine->List(aState.mPresContext, stdout, gNoiseIndent+1);
diff --git a/mozilla/layout/html/base/src/nsBlockReflowState.cpp b/mozilla/layout/html/base/src/nsBlockReflowState.cpp
index c50305ea44f..91c1ec4c672 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowState.cpp
+++ b/mozilla/layout/html/base/src/nsBlockReflowState.cpp
@@ -3822,7 +3822,12 @@ nsBlockFrame::SplitLine(nsBlockReflowState& aState,
   if (gNoisyReflow) {
     nsFrame::IndentBy(stdout, gNoiseIndent);
     printf("split line: from line=%p pushCount=%d aFrame=", aLine, pushCount);
-    nsFrame::ListTag(stdout, aFrame);
+    if (aFrame) {
+      nsFrame::ListTag(stdout, aFrame);
+    }
+    else {
+      printf("(null)");
+    }
     printf("\n");
     if (gReallyNoisyReflow) {
       aLine->List(aState.mPresContext, stdout, gNoiseIndent+1);
diff --git a/mozilla/layout/html/base/src/nsBlockReflowState.h b/mozilla/layout/html/base/src/nsBlockReflowState.h
index c50305ea44f..91c1ec4c672 100644
--- a/mozilla/layout/html/base/src/nsBlockReflowState.h
+++ b/mozilla/layout/html/base/src/nsBlockReflowState.h
@@ -3822,7 +3822,12 @@ nsBlockFrame::SplitLine(nsBlockReflowState& aState,
   if (gNoisyReflow) {
     nsFrame::IndentBy(stdout, gNoiseIndent);
     printf("split line: from line=%p pushCount=%d aFrame=", aLine, pushCount);
-    nsFrame::ListTag(stdout, aFrame);
+    if (aFrame) {
+      nsFrame::ListTag(stdout, aFrame);
+    }
+    else {
+      printf("(null)");
+    }
     printf("\n");
     if (gReallyNoisyReflow) {
       aLine->List(aState.mPresContext, stdout, gNoiseIndent+1);
diff --git a/mozilla/layout/html/base/src/nsLineLayout.cpp b/mozilla/layout/html/base/src/nsLineLayout.cpp
index d42550ec4e8..e5a75118813 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.cpp
+++ b/mozilla/layout/html/base/src/nsLineLayout.cpp
@@ -113,6 +113,7 @@ nsLineLayout::nsLineLayout(nsIPresContext& aPresContext,
   mColumn = 0;
   mEndsInWhiteSpace = PR_TRUE;
   mUnderstandsWhiteSpace = PR_FALSE;
+  mTextStartsWithNBSP = PR_FALSE;
   mFirstLetterStyleOK = PR_FALSE;
   mIsTopOfPage = PR_FALSE;
   mUpdatedBand = PR_FALSE;
@@ -270,6 +271,7 @@ nsLineLayout::BeginLineReflow(nscoord aX, nscoord aY,
   mColumn = 0;
   mEndsInWhiteSpace = PR_TRUE;
   mUnderstandsWhiteSpace = PR_FALSE;
+  mTextStartsWithNBSP = PR_FALSE;
   mFirstLetterStyleOK = PR_FALSE;
   mIsTopOfPage = aIsTopOfPage;
   mUpdatedBand = PR_FALSE;
@@ -411,6 +413,7 @@ nsLineLayout::UpdateBand(nscoord aX, nscoord aY,
   mLastFloaterWasLetterFrame = nsLayoutAtoms::letterFrame == frameType.get();
 
   // Now update all of the open spans...
+  mRootSpan->mContainsFloater = PR_TRUE;              // make sure mRootSpan gets updated too
   psd = mCurrentSpan;
   while (psd != mRootSpan) {
     NS_ASSERTION(nsnull != psd, "null ptr");
@@ -424,6 +427,7 @@ nsLineLayout::UpdateBand(nscoord aX, nscoord aY,
     else {
       psd->mRightEdge += deltaWidth;
     }
+    psd->mContainsFloater = PR_TRUE;
 #ifdef NOISY_REFLOW
     printf("  span %p: oldRightEdge=%d newRightEdge=%d\n",
            psd, psd->mRightEdge - deltaWidth, psd->mRightEdge);
@@ -479,6 +483,8 @@ nsLineLayout::NewPerSpanData(PerSpanData** aResult)
   psd->mFrame = nsnull;
   psd->mFirstFrame = nsnull;
   psd->mLastFrame = nsnull;
+  psd->mContainsFloater = PR_FALSE;
+  psd->mZeroEffectiveSpanBox = PR_FALSE;
 
 #ifdef DEBUG
   mSpansAllocated++;
@@ -514,7 +520,6 @@ nsLineLayout::BeginSpan(nsIFrame* aFrame,
     psd->mLeftEdge = aLeftEdge;
     psd->mX = aLeftEdge;
     psd->mRightEdge = aRightEdge;
-    psd->mZeroEffectiveSpanBox = PR_FALSE;
 
     const nsStyleText* styleText;
     aSpanReflowState->frame->GetStyleData(eStyleStruct_Text,
@@ -879,6 +884,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
   reflowState.mLineLayout = this;
   reflowState.isTopOfPage = mIsTopOfPage;
   mUnderstandsWhiteSpace = PR_FALSE;
+  mTextStartsWithNBSP = PR_FALSE;
 
   // Stash copies of some of the computed state away for later
   // (vertical alignment, for example)
@@ -1095,8 +1101,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
 
     // See if we can place the frame. If we can't fit it, then we
     // return now.
-    if (CanPlaceFrame(pfd, reflowState, notSafeToBreak, metrics,
-                      aReflowStatus)) {
+    if (CanPlaceFrame(pfd, reflowState, notSafeToBreak, metrics, aReflowStatus)) {
       // Place the frame, updating aBounds with the final size and
       // location.  Then apply the bottom+right margins (as
       // appropriate) to the frame.
@@ -1116,6 +1121,7 @@ nsLineLayout::ReflowFrame(nsIFrame* aFrame,
   else {
     PushFrame(aFrame);
   }
+  mTextStartsWithNBSP = PR_FALSE;           // reset for next time
 
 #ifdef REALLY_NOISY_REFLOW
   nsFrame::IndentBy(stdout, mSpanDepth);
@@ -1234,7 +1240,7 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
 
   PerSpanData* psd = mCurrentSpan;
   if (psd->mNoWrap) {
-    // When wrapping is off, everything fits
+    // When wrapping is off, everything fits.
     return PR_TRUE;
   }
 
@@ -1345,6 +1351,43 @@ nsLineLayout::CanPlaceFrame(PerFrameData* pfd,
     }
   }
 
+  // Special check for span frames
+  if (pfd->mSpan && pfd->mSpan->mContainsFloater) {
+    // If the span either directly or indirectly contains a floater then
+    // it fits. Why? It's kind of complicated, but here goes:
+    //
+    // 1. CanPlaceFrame is used for all frame placements on a line,
+    // and in a span. This includes recursively placement of frames
+    // inside of spans, and the span itself. Because the logic always
+    // checks for room before proceeding (the code above here), the
+    // only things on a line will be those things that "fit".
+    //
+    // 2. Before a floater is placed on a line, the line has to be empty
+    // (otherwise its a "below current line" flaoter and will be placed
+    // after the line).
+    //
+    // Therefore, if the span directly or indirectly has a floater
+    // then it means that at the time of the placement of the floater
+    // the line was empty. Because of #1, only the frames that fit can
+    // be added after that point, therefore we can assume that the
+    // current span being placed has fit.
+    //
+    // So how do we get here and have a span that should already fit
+    // and yet doesn't: Simple: span's that have the no-wrap attribute
+    // set on them and contain a floater and are placed where they
+    // don't naturally fit.
+    return PR_TRUE;
+ }
+
+  // Yet another special check. If the text happens to have started
+  // with a non-breaking space, then we make it sticky on its left
+  // edge...Which means that whatever piece of text we just formatted
+  // will be the piece that fits (the text frame logic knows to stop
+  // when it runs out of room).
+  if (pfd->mIsNonEmptyTextFrame && mTextStartsWithNBSP) {
+    return PR_TRUE;
+  }
+
 #ifdef NOISY_CAN_PLACE_FRAME
   printf("   ==> didn't fit\n");
 #endif
diff --git a/mozilla/layout/html/base/src/nsLineLayout.h b/mozilla/layout/html/base/src/nsLineLayout.h
index 7426f332de6..e12a094363b 100644
--- a/mozilla/layout/html/base/src/nsLineLayout.h
+++ b/mozilla/layout/html/base/src/nsLineLayout.h
@@ -128,6 +128,10 @@ public:
     mUnderstandsWhiteSpace = aSetting;
   }
 
+  void SetTextStartsWithNBSP(PRBool aYes) {
+    mTextStartsWithNBSP = aYes;
+  }
+
   void RecordWordFrame(nsIFrame* aWordFrame) {
     mWordFrames.AppendElement(aWordFrame);
   }
@@ -222,6 +226,7 @@ protected:
   PRInt32 mColumn;
   PRBool mEndsInWhiteSpace;
   PRBool mUnderstandsWhiteSpace;
+  PRBool mTextStartsWithNBSP;
   PRBool mFirstLetterStyleOK;
   PRBool mIsTopOfPage;
   PRBool mUpdatedBand;
@@ -317,6 +322,7 @@ public:
     PRUint8 mDirection;
     PRBool mChangedFrameDirection;
     PRBool mZeroEffectiveSpanBox;
+    PRBool mContainsFloater;
 
     nscoord mLeftEdge;
     nscoord mX;
diff --git a/mozilla/layout/html/base/src/nsTextFrame.cpp b/mozilla/layout/html/base/src/nsTextFrame.cpp
index f354552c77e..771daf6404d 100644
--- a/mozilla/layout/html/base/src/nsTextFrame.cpp
+++ b/mozilla/layout/html/base/src/nsTextFrame.cpp
@@ -2818,6 +2818,8 @@ nsTextFrame::Reflow(nsIPresContext& aPresContext,
     }
   }
 
+  PRBool firstThing = PR_TRUE;
+  PRBool textStartsWithNBSP = PR_FALSE;
   for (;;) {
     // Get next word/whitespace from the text
     PRBool isWhitespace;
@@ -2886,8 +2888,16 @@ nsTextFrame::Reflow(nsIPresContext& aPresContext,
         }
         lastWordWidth = width;
       }
+
+      // See if the first thing in the section of text is a
+      // non-breaking space (html nbsp entity). If it is then make
+      // note of that fact for the line layout logic.
+      if (wrapping && firstThing && (bp[0] == ' ')) {
+        textStartsWithNBSP = PR_TRUE;
+      }
       skipWhitespace = PR_FALSE;
     }
+    firstThing = PR_FALSE;
 
     // See if there is room for the text
     if (measureText) {
@@ -3050,6 +3060,7 @@ nsTextFrame::Reflow(nsIPresContext& aPresContext,
   // text object collapsed into nothingness which means it shouldn't
   // effect the current setting of the ends-in-whitespace flag.
   lineLayout.SetUnderstandsWhiteSpace(PR_TRUE);
+  lineLayout.SetTextStartsWithNBSP(textStartsWithNBSP);
   if (0 != x) {
     lineLayout.SetEndsInWhiteSpace(endsInWhitespace);
   }