Bug 59200. Merge floater reflow and placement into FlowAndPlaceFloater() to deal with the fact that a floater may need to be reflowed as its 'pushed' to a new location. For auto-width floaters, ensure that the floater is not flowed at a width less than its max-element-size. Enforce CSS2 section 9.5.1 rule [2] by maintaining mLastFloaterY in the reflow state. r=rbs, sr=attinasi.

layout/generic/nsBlockFrame.cpp

@@ -4122,18 +4122,10 @@ nsBlockFrame::PostPlaceLine(nsBlockReflowState& aState,
     printf(": line=%p xmost=%d\n", aLine, xmost);
   }
 #endif
-  // If we're shrink wrapping our width and the line was wrapped,
-  // then make sure we take up all of the available width
-  if (aState.GetFlag(BRS_SHRINKWRAPWIDTH) && aLine->IsLineWrapped()) {
-    aState.mKidXMost = aState.BorderPadding().left + aState.mContentArea.width;
-#ifdef NOISY_KIDXMOST
-    printf("%p PostPlaceLine A aState.mKidXMost=%d\n", this, aState.mKidXMost); 
-#endif
-  }
-  else if (xmost > aState.mKidXMost) {
+  if (xmost > aState.mKidXMost) {
     aState.mKidXMost = xmost;
 #ifdef NOISY_KIDXMOST
-    printf("%p PostPlaceLine B aState.mKidXMost=%d\n", this, aState.mKidXMost); 
+    printf("%p PostPlaceLine aState.mKidXMost=%d\n", this, aState.mKidXMost); 
 #endif
   }
 }
@@ -4778,10 +4770,14 @@ nsBlockFrame::DeleteChildsNextInFlow(nsIPresContext* aPresContext,
 nsresult
 nsBlockFrame::ReflowFloater(nsBlockReflowState& aState,
                             nsPlaceholderFrame* aPlaceholder,
-                            nsRect& aCombinedRect,
+                            nsRect& aCombinedRectResult,
                             nsMargin& aMarginResult,
-                            nsMargin& aComputedOffsetsResult)
+                            nsMargin& aComputedOffsetsResult,
+                            nscoord& aMaxElementWidthResult)
 {
+  // Reflow the floater.
+  nsIFrame* floater = aPlaceholder->GetOutOfFlowFrame();
+
 #ifdef NOISY_FLOATER
   printf("Reflow Floater %p in parent %p, availSpace(%d,%d,%d,%d)\n",
           aPlaceholder->GetOutOfFlowFrame(), this, 
@@ -4789,40 +4785,81 @@ nsBlockFrame::ReflowFloater(nsBlockReflowState& aState,
           aState.mAvailSpaceRect.width, aState.mAvailSpaceRect.height
   );
 #endif
-  // XXX update this just
-  aState.GetAvailableSpace();
 
-  // Reflow the floater. Since floaters are continued we given them an
-  // unbounded height. Floaters with an auto width are sized to zero
-  // according to the css2 spec.
-  // XXX We also need to take into account whether we should clear any
-  // preceeding floaters...
+  // Compute the available width. By default, assume the width of the
+  // available space rect.
+  nscoord availWidth = aState.mAvailSpaceRect.width;
+
+  // If the floater's width is automatic, we can't let the floater's
+  // width shrink below its maxElementSize.
+  const nsStylePosition* position;
+  GetStyleData(eStyleStruct_Position, NS_REINTERPRET_CAST(const nsStyleStruct*&, position));
+
+  PRBool isAutoWidth = (eStyleUnit_Auto == position->mWidth.GetUnit());
+  if (isAutoWidth) {
+    // It's auto-width. Have we computed a max element size yet? (If
+    // not, the floater cache will have NS_UNCONSTRAINEDSIZE as the
+    // initial value.) If we _have_ computed a max element size, and
+    // its larger then the available width, pin the avaiable width to
+    // the maxElementSize.
+    if ((NS_UNCONSTRAINEDSIZE != aMaxElementWidthResult) &&
+        (aMaxElementWidthResult > availWidth)) {
+      availWidth = aMaxElementWidthResult;
+    }
+  }
+
+  // We'll need to compute the max element size if either 1) we're
+  // auto-width and we've not yet cached the value, or 2) the state
+  // wanted us to compute it anyway.
+  PRBool computeMaxElementSize =
+    (isAutoWidth && (NS_UNCONSTRAINEDSIZE == aMaxElementWidthResult)) ||
+    aState.GetFlag(BRS_COMPUTEMAXELEMENTSIZE);
+
   // XXX Why do we have to add in our border/padding?
   nsRect availSpace(aState.mAvailSpaceRect.x + aState.BorderPadding().left,
                     aState.mAvailSpaceRect.y + aState.BorderPadding().top,
-                    aState.mAvailSpaceRect.width, NS_UNCONSTRAINEDSIZE);
-  nsIFrame* floater = aPlaceholder->GetOutOfFlowFrame();
-  PRBool isAdjacentWithTop = aState.IsAdjacentWithTop();
+                    availWidth, NS_UNCONSTRAINEDSIZE);
 
-  // Setup block reflow state to reflow the floater
+  // Setup a block reflow state to reflow the floater.
   nsBlockReflowContext brc(aState.mPresContext, aState.mReflowState,
-                           aState.GetFlag(BRS_COMPUTEMAXELEMENTSIZE),
+                           computeMaxElementSize,
                            aState.GetFlag(BRS_COMPUTEMAXWIDTH));
+
   brc.SetNextRCFrame(aState.mNextRCFrame);
 
   // Reflow the floater
+  PRBool isAdjacentWithTop = aState.IsAdjacentWithTop();
+
   nsReflowStatus frameReflowStatus;
-  nsresult rv = brc.ReflowBlock(floater, availSpace, PR_TRUE, 0,
-                                isAdjacentWithTop,
+  nsresult rv = brc.ReflowBlock(floater, availSpace, PR_TRUE, 0, isAdjacentWithTop,
                                 aComputedOffsetsResult, frameReflowStatus);
-  if (PR_TRUE==brc.BlockShouldInvalidateItself()) {
+
+  if (NS_SUCCEEDED(rv) && isAutoWidth && (NS_UNCONSTRAINEDSIZE == aMaxElementWidthResult)) {
+    // We've just flowed an auto-width floater, but have not yet cached
+    // the maxElementSize. Do so now.
+    nsSize maxElementSize = brc.GetMaxElementSize();
+    aMaxElementWidthResult = maxElementSize.width;
+
+    if (aMaxElementWidthResult > availSpace.width) {
+      // The floater's maxElementSize is larger than the available
+      // width. Reflow it again, this time pinning the width to the
+      // maxElementSize.
+      availSpace.width = aMaxElementWidthResult;
+      rv = brc.ReflowBlock(floater, availSpace, PR_TRUE, 0, isAdjacentWithTop,
+                           aComputedOffsetsResult, frameReflowStatus);
+    }
+  }
+
+  if (brc.BlockShouldInvalidateItself()) {
     Invalidate(aState.mPresContext, mRect);
   }
+
   if (floater == aState.mNextRCFrame) {
-    // NULL out mNextRCFrame so if we reflow it again we don't think it's still
-    // an incremental reflow
+    // Null out mNextRCFrame so if we reflow it again, we don't think
+    // it's still an incremental reflow
     aState.mNextRCFrame = nsnull;
   }
+
   if (NS_FAILED(rv)) {
     return rv;
   }
@@ -4837,7 +4874,8 @@ nsBlockFrame::ReflowFloater(nsBlockReflowState& aState,
   aMarginResult.left = m.left;
 
   const nsHTMLReflowMetrics& metrics = brc.GetMetrics();
-  aCombinedRect = metrics.mOverflowArea;
+  aCombinedRectResult = metrics.mOverflowArea;
+
   // Set the rect, make sure the view is properly sized and positioned,
   // and tell the frame we're done reflowing it
   floater->SizeTo(aState.mPresContext, metrics.width, metrics.height);

layout/generic/nsBlockFrame.h

@@ -351,9 +351,10 @@ protected:
 
   nsresult ReflowFloater(nsBlockReflowState& aState,
                          nsPlaceholderFrame* aPlaceholder,
-                         nsRect& aCombinedRect,
+                         nsRect& aCombinedRectResult,
                          nsMargin& aMarginResult,
-                         nsMargin& aComputedOffsetsResult);
+                         nsMargin& aComputedOffsetsResult,
+                         nscoord& aMaxElementWidthResult);
 
   //----------------------------------------
   // Methods for pushing/pulling lines/frames
@@ -482,9 +483,5 @@ protected:
 #endif
 };
 
-// Some #ifdef'd bug fixes
-#define FIX_BUG_38157 
-#define FIX_BUG_37657
-
 #endif /* nsBlockFrame_h___ */
 

layout/generic/nsBlockReflowContext.cpp

@@ -314,8 +314,10 @@ nsBlockReflowContext::ReflowBlock(nsIFrame* aFrame,
                            (const nsStyleStruct*&)display);
   if ((eStyleUnit_Auto == widthUnit) &&
       ((NS_STYLE_FLOAT_LEFT == display->mFloats) ||
-       (NS_STYLE_FLOAT_RIGHT == display->mFloats)))
-  {
+       (NS_STYLE_FLOAT_RIGHT == display->mFloats))) {
+    // Construct the reflow state using the ctor that explicitly
+    // constrains the containing block's width and height to the
+    // available width and height.
     nsHTMLReflowState autoReflowState(mPresContext, mOuterReflowState, aFrame,
                                       availSpace, aSpace.width, aSpace.height);
     autoReflowState.reason = reason;
@@ -325,8 +327,10 @@ nsBlockReflowContext::ReflowBlock(nsIFrame* aFrame,
                        aComputedOffsets,
                        aFrameReflowStatus);
   }
-  else
-  {
+  else {
+    // Construct the reflow state using the ctor that will use the
+    // containing block's computed width and height (or handle derive
+    // appropriate values for an absolutely positioned frame).
     nsHTMLReflowState normalReflowState(mPresContext, mOuterReflowState, aFrame,
                                         availSpace, reason);
     rv = DoReflowBlock(normalReflowState, reason, aFrame, aSpace, 

layout/generic/nsBlockReflowState.cpp

@@ -43,6 +43,7 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
   : mBlock(aFrame),
     mPresContext(aPresContext),
     mReflowState(aReflowState),
+    mLastFloaterY(0),
     mNextRCFrame(nsnull),
     mPrevBottomMargin(0),
     mLineNumber(0),
@@ -93,18 +94,7 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
     else if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxWidth) {
       // Choose a width based on the content (shrink wrap width) up
       // to the maximum width
-      // Part 2 of a possible fix for 38157
-#ifdef FIX_BUG_38157
-      const nsMargin& margin = Margin();
-      nscoord availContentWidth = aReflowState.availableWidth;
-      if (NS_UNCONSTRAINEDSIZE != availContentWidth) {
-        availContentWidth -= (borderPadding.left + borderPadding.right) +
-                             (margin.left + margin.right);
-      }       
-      mContentArea.width = PR_MIN(aReflowState.mComputedMaxWidth, availContentWidth);
-#else
       mContentArea.width = aReflowState.mComputedMaxWidth;
-#endif
       SetFlag(BRS_SHRINKWRAPWIDTH, PR_TRUE);
     }
     else {
@@ -606,6 +596,7 @@ nsBlockReflowState::RecoverStateFrom(nsLineBox* aLine,
       }
 #endif
       mSpaceManager->AddRectRegion(floater, fc->mRegion);
+      mLastFloaterY = fc->mRegion.y;
       fc = fc->Next();
     }
 #ifdef DEBUG
@@ -702,13 +693,9 @@ nsBlockReflowState::AddFloater(nsLineLayout& aLineLayout,
     nscoord dy = oy - mSpaceManagerY;
     mSpaceManager->Translate(-dx, -dy);
 
-    // Reflow the floater
-    mBlock->ReflowFloater(*this, aPlaceholder, fc->mCombinedArea,
-                          fc->mMargins, fc->mOffsets);
-
     // And then place it
     PRBool isLeftFloater;
-    PlaceFloater(fc, &isLeftFloater);
+    FlowAndPlaceFloater(fc, &isLeftFloater);    
 
     // Pass on updated available space to the current inline reflow engine
     GetAvailableSpace();
@@ -907,8 +894,8 @@ nsBlockReflowState::CanPlaceFloater(const nsRect& aFloaterRect,
 }
 
 void
-nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
-                                 PRBool* aIsLeftFloater)
+nsBlockReflowState::FlowAndPlaceFloater(nsFloaterCache* aFloaterCache,
+                                        PRBool* aIsLeftFloater)
 {
   // Save away the Y coordinate before placing the floater. We will
   // restore mY at the end after placing the floater. This is
@@ -916,9 +903,14 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
   // placement are for the floater only, not for any non-floating
   // content.
   nscoord saveY = mY;
+
+  // Grab the compatibility mode
+  nsCompatibility mode;
+  mPresContext->GetCompatibilityMode(&mode);
+
   nsIFrame* floater = aFloaterCache->mPlaceholder->GetOutOfFlowFrame();
 
-  // Get the type of floater
+  // Grab the floater's display information
   const nsStyleDisplay* floaterDisplay;
   const nsStylePosition* floaterPosition;
   floater->GetStyleData(eStyleStruct_Display,
@@ -926,59 +918,72 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
   floater->GetStyleData(eStyleStruct_Position,
                         (const nsStyleStruct*&)floaterPosition);
 
-  // See if the floater should clear any preceeding floaters...
-  if (NS_STYLE_CLEAR_NONE != floaterDisplay->mBreakType) {
-    ClearFloaters(mY, floaterDisplay->mBreakType);
-  }
-  else {
-    // Get the band of available space
-    GetAvailableSpace();
-  }
-
-  // Get the floaters bounding box and margin information
+  // This will hold the floater's geometry when we've found a place
+  // for it to live.
   nsRect region;
-  floater->GetRect(region);
 
-  // Adjust the floater size by its margin. That's the area that will
-  // impact the space manager.
-  region.width += aFloaterCache->mMargins.left + aFloaterCache->mMargins.right;
-  region.height += aFloaterCache->mMargins.top + aFloaterCache->mMargins.bottom;
+  // Advance mY to mLastFloaterY (if it's not past it already) to
+  // enforce 9.5.1 rule [2]; i.e., make sure that a float isn't
+  // ``above'' another float that preceded it in the flow.
+  mY = NS_MAX(mLastFloaterY, mY);
 
-  // Find a place to place the floater. The CSS2 spec doesn't want
-  // floaters overlapping each other or sticking out of the containing
-  // block if possible (CSS2 spec section 9.5.1, see the rule list).
-  NS_ASSERTION((NS_STYLE_FLOAT_LEFT == floaterDisplay->mFloats) ||
-               (NS_STYLE_FLOAT_RIGHT == floaterDisplay->mFloats),
-               "invalid float type");
-
-  // While there is not enough room for the floater, clear past other
-  // floaters until there is room (or the band is not impacted by a
-  // floater).
-  // 
-  // Note: The CSS2 spec says that floaters should be placed as high
-  // as possible.
-  //
-#ifdef FIX_BUG_37657
-  // Also note that in backwards compatibility mode, we skip this step
-  // for tables, since in old browsers, floating tables are horizontally
-  // stacked regardless of available space.  (See bug 43086 about
-  // tables vs. non-tables.)
-  nsCompatibility mode;
-  mPresContext->GetCompatibilityMode(&mode);
-  if ((eCompatibility_NavQuirks != mode) ||
-      (NS_STYLE_DISPLAY_TABLE != floaterDisplay->mDisplay)) {
-    while (!CanPlaceFloater(region, floaterDisplay->mFloats)) {
-      mY += mAvailSpaceRect.height;
+  while (1) {
+    // See if the floater should clear any preceeding floaters...
+    if (NS_STYLE_CLEAR_NONE != floaterDisplay->mBreakType) {
+      ClearFloaters(mY, floaterDisplay->mBreakType);
+    }
+    else {
+      // Get the band of available space
       GetAvailableSpace();
     }
-  }
-#else
-  while (!CanPlaceFloater(region, floaterDisplay->mFloats)) {
-    mY += mAvailSpaceRect.height;
-    GetAvailableSpace();
-  }
+
+    // Reflow the floater
+    mBlock->ReflowFloater(*this, aFloaterCache->mPlaceholder, aFloaterCache->mCombinedArea,
+                          aFloaterCache->mMargins, aFloaterCache->mOffsets,
+                          aFloaterCache->mMaxElementWidth);
+
+    // Get the floaters bounding box and margin information
+    floater->GetRect(region);
+
+#ifdef DEBUG
+    if (nsBlockFrame::gNoisyReflow) {
+      nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
+      printf("flowed floater: ");
+      nsFrame::ListTag(stdout, floater);
+      printf(" (%d,%d,%d,%d), max-element-width=%d\n",
+             region.x, region.y, region.width, region.height,
+             aFloaterCache->mMaxElementWidth);
+    }
 #endif
 
+    // Adjust the floater size by its margin. That's the area that will
+    // impact the space manager.
+    region.width += aFloaterCache->mMargins.left + aFloaterCache->mMargins.right;
+    region.height += aFloaterCache->mMargins.top + aFloaterCache->mMargins.bottom;
+
+    // Find a place to place the floater. The CSS2 spec doesn't want
+    // floaters overlapping each other or sticking out of the containing
+    // block if possible (CSS2 spec section 9.5.1, see the rule list).
+    NS_ASSERTION((NS_STYLE_FLOAT_LEFT == floaterDisplay->mFloats) ||
+                 (NS_STYLE_FLOAT_RIGHT == floaterDisplay->mFloats),
+                 "invalid float type");
+
+    // In backwards compatibility mode, we don't bother to see if a
+    // floated table can ``really'' fit: in old browsers, floating
+    // tables are horizontally stacked regardless of available space.
+    // (See bug 43086 about tables vs. non-tables.)
+    if ((eCompatibility_NavQuirks == mode) &&
+        (NS_STYLE_DISPLAY_TABLE == floaterDisplay->mDisplay))
+      break;
+
+    // Can the floater fit here?
+    if (CanPlaceFloater(region, floaterDisplay->mFloats))
+        break;
+
+    // Nope. Advance to the next band.
+    mY += mAvailSpaceRect.height;
+  }
+
   // Assign an x and y coordinate to the floater. Note that the x,y
   // coordinates are computed <b>relative to the translation in the
   // spacemanager</b> which means that the impacted region will be
@@ -1082,6 +1087,9 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
     nsBlockFrame::CombineRects(combinedArea, mFloaterCombinedArea);
   }
 
+  // Remember the y-coordinate of the floater we've just placed
+  mLastFloaterY = mY;
+
   // Now restore mY
   mY = saveY;
 
@@ -1091,7 +1099,7 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
     floater->GetRect(r);
     nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
     printf("placed floater: ");
-    ((nsFrame*)floater)->ListTag(stdout);
+    nsFrame::ListTag(stdout, floater);
     printf(" %d,%d,%d,%d\n", r.x, r.y, r.width, r.height);
   }
 #endif
@@ -1114,12 +1122,10 @@ nsBlockReflowState::PlaceBelowCurrentLineFloaters(nsFloaterCacheList& aList)
         printf("\n");
       }
 #endif
-      mBlock->ReflowFloater(*this, fc->mPlaceholder, fc->mCombinedArea,
-                            fc->mMargins, fc->mOffsets);
 
       // Place the floater
       PRBool isLeftFloater;
-      PlaceFloater(fc, &isLeftFloater);
+      FlowAndPlaceFloater(fc, &isLeftFloater);
     }
     fc = fc->Next();
   }

layout/generic/nsBlockReflowState.h

@@ -65,8 +65,8 @@ public:
 
   PRBool CanPlaceFloater(const nsRect& aFloaterRect, PRUint8 aFloats);
 
-  void PlaceFloater(nsFloaterCache* aFloaterCache,
-                    PRBool* aIsLeftFloater);
+  void FlowAndPlaceFloater(nsFloaterCache* aFloaterCache,
+                           PRBool* aIsLeftFloater);
 
   void PlaceBelowCurrentLineFloaters(nsFloaterCacheList& aFloaters);
 
@@ -177,6 +177,10 @@ public:
   // The combined area of all floaters placed so far
   nsRect mFloaterCombinedArea;
 
+  // The y-coordinate of the last floater placed. We keep this around
+  // to enforce 9.5.1 rule [2]
+  nscoord mLastFloaterY;
+
   // For unconstained-width reflow, we keep the right floaters
   // combined area stored seperately.
   PRBool mHaveRightFloaters;

layout/generic/nsInlineFrame.cpp

@@ -355,20 +355,20 @@ NS_IMETHODIMP
 nsInlineFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
 {
   // The inline container frame does not handle the reflow
-  // request.  It passes it up to its parent container.  
+  // request.  It passes it up to its parent container.
 
   // If you don't already have dirty children,
   if (!(mState & NS_FRAME_HAS_DIRTY_CHILDREN)) {
     if (mParent) {
-      // Record that you are dirty and have dirty children    
+      // Record that you are dirty and have dirty children
       mState |= NS_FRAME_IS_DIRTY;
-      mState |= NS_FRAME_HAS_DIRTY_CHILDREN;      
+      mState |= NS_FRAME_HAS_DIRTY_CHILDREN; 
 
-      // Pass the reflow request up to the parent    
-      mParent->ReflowDirtyChild(aPresShell, (nsIFrame*) this);
+      // Pass the reflow request up to the parent
+      mParent->ReflowDirtyChild(aPresShell, this);
     }
     else {
-      NS_ASSERTION(0, "No parent to pass the reflow request up to.");
+      NS_ERROR("No parent to pass the reflow request up to.");
     }
   }
 

layout/generic/nsLineBox.cpp

@@ -1097,6 +1097,7 @@ nsFloaterCache::nsFloaterCache()
     mMargins(0, 0, 0, 0),
     mOffsets(0, 0, 0, 0),
     mCombinedArea(0, 0, 0, 0),
+    mMaxElementWidth(NS_UNCONSTRAINEDSIZE),
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsFloaterCache);

layout/generic/nsLineBox.h

@@ -67,6 +67,9 @@ public:
   // the containing block frame.
   nsRect mCombinedArea;
 
+  // The max element size for the floater.
+  nscoord mMaxElementWidth;
+
 protected:
   nsFloaterCache* mNext;
 

layout/html/base/src/nsBlockFrame.cpp

@@ -4122,18 +4122,10 @@ nsBlockFrame::PostPlaceLine(nsBlockReflowState& aState,
     printf(": line=%p xmost=%d\n", aLine, xmost);
   }
 #endif
-  // If we're shrink wrapping our width and the line was wrapped,
-  // then make sure we take up all of the available width
-  if (aState.GetFlag(BRS_SHRINKWRAPWIDTH) && aLine->IsLineWrapped()) {
-    aState.mKidXMost = aState.BorderPadding().left + aState.mContentArea.width;
-#ifdef NOISY_KIDXMOST
-    printf("%p PostPlaceLine A aState.mKidXMost=%d\n", this, aState.mKidXMost); 
-#endif
-  }
-  else if (xmost > aState.mKidXMost) {
+  if (xmost > aState.mKidXMost) {
     aState.mKidXMost = xmost;
 #ifdef NOISY_KIDXMOST
-    printf("%p PostPlaceLine B aState.mKidXMost=%d\n", this, aState.mKidXMost); 
+    printf("%p PostPlaceLine aState.mKidXMost=%d\n", this, aState.mKidXMost); 
 #endif
   }
 }
@@ -4778,10 +4770,14 @@ nsBlockFrame::DeleteChildsNextInFlow(nsIPresContext* aPresContext,
 nsresult
 nsBlockFrame::ReflowFloater(nsBlockReflowState& aState,
                             nsPlaceholderFrame* aPlaceholder,
-                            nsRect& aCombinedRect,
+                            nsRect& aCombinedRectResult,
                             nsMargin& aMarginResult,
-                            nsMargin& aComputedOffsetsResult)
+                            nsMargin& aComputedOffsetsResult,
+                            nscoord& aMaxElementWidthResult)
 {
+  // Reflow the floater.
+  nsIFrame* floater = aPlaceholder->GetOutOfFlowFrame();
+
 #ifdef NOISY_FLOATER
   printf("Reflow Floater %p in parent %p, availSpace(%d,%d,%d,%d)\n",
           aPlaceholder->GetOutOfFlowFrame(), this, 
@@ -4789,40 +4785,81 @@ nsBlockFrame::ReflowFloater(nsBlockReflowState& aState,
           aState.mAvailSpaceRect.width, aState.mAvailSpaceRect.height
   );
 #endif
-  // XXX update this just
-  aState.GetAvailableSpace();
 
-  // Reflow the floater. Since floaters are continued we given them an
-  // unbounded height. Floaters with an auto width are sized to zero
-  // according to the css2 spec.
-  // XXX We also need to take into account whether we should clear any
-  // preceeding floaters...
+  // Compute the available width. By default, assume the width of the
+  // available space rect.
+  nscoord availWidth = aState.mAvailSpaceRect.width;
+
+  // If the floater's width is automatic, we can't let the floater's
+  // width shrink below its maxElementSize.
+  const nsStylePosition* position;
+  GetStyleData(eStyleStruct_Position, NS_REINTERPRET_CAST(const nsStyleStruct*&, position));
+
+  PRBool isAutoWidth = (eStyleUnit_Auto == position->mWidth.GetUnit());
+  if (isAutoWidth) {
+    // It's auto-width. Have we computed a max element size yet? (If
+    // not, the floater cache will have NS_UNCONSTRAINEDSIZE as the
+    // initial value.) If we _have_ computed a max element size, and
+    // its larger then the available width, pin the avaiable width to
+    // the maxElementSize.
+    if ((NS_UNCONSTRAINEDSIZE != aMaxElementWidthResult) &&
+        (aMaxElementWidthResult > availWidth)) {
+      availWidth = aMaxElementWidthResult;
+    }
+  }
+
+  // We'll need to compute the max element size if either 1) we're
+  // auto-width and we've not yet cached the value, or 2) the state
+  // wanted us to compute it anyway.
+  PRBool computeMaxElementSize =
+    (isAutoWidth && (NS_UNCONSTRAINEDSIZE == aMaxElementWidthResult)) ||
+    aState.GetFlag(BRS_COMPUTEMAXELEMENTSIZE);
+
   // XXX Why do we have to add in our border/padding?
   nsRect availSpace(aState.mAvailSpaceRect.x + aState.BorderPadding().left,
                     aState.mAvailSpaceRect.y + aState.BorderPadding().top,
-                    aState.mAvailSpaceRect.width, NS_UNCONSTRAINEDSIZE);
-  nsIFrame* floater = aPlaceholder->GetOutOfFlowFrame();
-  PRBool isAdjacentWithTop = aState.IsAdjacentWithTop();
+                    availWidth, NS_UNCONSTRAINEDSIZE);
 
-  // Setup block reflow state to reflow the floater
+  // Setup a block reflow state to reflow the floater.
   nsBlockReflowContext brc(aState.mPresContext, aState.mReflowState,
-                           aState.GetFlag(BRS_COMPUTEMAXELEMENTSIZE),
+                           computeMaxElementSize,
                            aState.GetFlag(BRS_COMPUTEMAXWIDTH));
+
   brc.SetNextRCFrame(aState.mNextRCFrame);
 
   // Reflow the floater
+  PRBool isAdjacentWithTop = aState.IsAdjacentWithTop();
+
   nsReflowStatus frameReflowStatus;
-  nsresult rv = brc.ReflowBlock(floater, availSpace, PR_TRUE, 0,
-                                isAdjacentWithTop,
+  nsresult rv = brc.ReflowBlock(floater, availSpace, PR_TRUE, 0, isAdjacentWithTop,
                                 aComputedOffsetsResult, frameReflowStatus);
-  if (PR_TRUE==brc.BlockShouldInvalidateItself()) {
+
+  if (NS_SUCCEEDED(rv) && isAutoWidth && (NS_UNCONSTRAINEDSIZE == aMaxElementWidthResult)) {
+    // We've just flowed an auto-width floater, but have not yet cached
+    // the maxElementSize. Do so now.
+    nsSize maxElementSize = brc.GetMaxElementSize();
+    aMaxElementWidthResult = maxElementSize.width;
+
+    if (aMaxElementWidthResult > availSpace.width) {
+      // The floater's maxElementSize is larger than the available
+      // width. Reflow it again, this time pinning the width to the
+      // maxElementSize.
+      availSpace.width = aMaxElementWidthResult;
+      rv = brc.ReflowBlock(floater, availSpace, PR_TRUE, 0, isAdjacentWithTop,
+                           aComputedOffsetsResult, frameReflowStatus);
+    }
+  }
+
+  if (brc.BlockShouldInvalidateItself()) {
     Invalidate(aState.mPresContext, mRect);
   }
+
   if (floater == aState.mNextRCFrame) {
-    // NULL out mNextRCFrame so if we reflow it again we don't think it's still
-    // an incremental reflow
+    // Null out mNextRCFrame so if we reflow it again, we don't think
+    // it's still an incremental reflow
     aState.mNextRCFrame = nsnull;
   }
+
   if (NS_FAILED(rv)) {
     return rv;
   }
@@ -4837,7 +4874,8 @@ nsBlockFrame::ReflowFloater(nsBlockReflowState& aState,
   aMarginResult.left = m.left;
 
   const nsHTMLReflowMetrics& metrics = brc.GetMetrics();
-  aCombinedRect = metrics.mOverflowArea;
+  aCombinedRectResult = metrics.mOverflowArea;
+
   // Set the rect, make sure the view is properly sized and positioned,
   // and tell the frame we're done reflowing it
   floater->SizeTo(aState.mPresContext, metrics.width, metrics.height);

layout/html/base/src/nsBlockFrame.h

@@ -351,9 +351,10 @@ protected:
 
   nsresult ReflowFloater(nsBlockReflowState& aState,
                          nsPlaceholderFrame* aPlaceholder,
-                         nsRect& aCombinedRect,
+                         nsRect& aCombinedRectResult,
                          nsMargin& aMarginResult,
-                         nsMargin& aComputedOffsetsResult);
+                         nsMargin& aComputedOffsetsResult,
+                         nscoord& aMaxElementWidthResult);
 
   //----------------------------------------
   // Methods for pushing/pulling lines/frames
@@ -482,9 +483,5 @@ protected:
 #endif
 };
 
-// Some #ifdef'd bug fixes
-#define FIX_BUG_38157 
-#define FIX_BUG_37657
-
 #endif /* nsBlockFrame_h___ */
 

layout/html/base/src/nsBlockReflowContext.cpp

@@ -314,8 +314,10 @@ nsBlockReflowContext::ReflowBlock(nsIFrame* aFrame,
                            (const nsStyleStruct*&)display);
   if ((eStyleUnit_Auto == widthUnit) &&
       ((NS_STYLE_FLOAT_LEFT == display->mFloats) ||
-       (NS_STYLE_FLOAT_RIGHT == display->mFloats)))
-  {
+       (NS_STYLE_FLOAT_RIGHT == display->mFloats))) {
+    // Construct the reflow state using the ctor that explicitly
+    // constrains the containing block's width and height to the
+    // available width and height.
     nsHTMLReflowState autoReflowState(mPresContext, mOuterReflowState, aFrame,
                                       availSpace, aSpace.width, aSpace.height);
     autoReflowState.reason = reason;
@@ -325,8 +327,10 @@ nsBlockReflowContext::ReflowBlock(nsIFrame* aFrame,
                        aComputedOffsets,
                        aFrameReflowStatus);
   }
-  else
-  {
+  else {
+    // Construct the reflow state using the ctor that will use the
+    // containing block's computed width and height (or handle derive
+    // appropriate values for an absolutely positioned frame).
     nsHTMLReflowState normalReflowState(mPresContext, mOuterReflowState, aFrame,
                                         availSpace, reason);
     rv = DoReflowBlock(normalReflowState, reason, aFrame, aSpace, 

layout/html/base/src/nsBlockReflowState.cpp

@@ -43,6 +43,7 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
   : mBlock(aFrame),
     mPresContext(aPresContext),
     mReflowState(aReflowState),
+    mLastFloaterY(0),
     mNextRCFrame(nsnull),
     mPrevBottomMargin(0),
     mLineNumber(0),
@@ -93,18 +94,7 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
     else if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxWidth) {
       // Choose a width based on the content (shrink wrap width) up
       // to the maximum width
-      // Part 2 of a possible fix for 38157
-#ifdef FIX_BUG_38157
-      const nsMargin& margin = Margin();
-      nscoord availContentWidth = aReflowState.availableWidth;
-      if (NS_UNCONSTRAINEDSIZE != availContentWidth) {
-        availContentWidth -= (borderPadding.left + borderPadding.right) +
-                             (margin.left + margin.right);
-      }       
-      mContentArea.width = PR_MIN(aReflowState.mComputedMaxWidth, availContentWidth);
-#else
       mContentArea.width = aReflowState.mComputedMaxWidth;
-#endif
       SetFlag(BRS_SHRINKWRAPWIDTH, PR_TRUE);
     }
     else {
@@ -606,6 +596,7 @@ nsBlockReflowState::RecoverStateFrom(nsLineBox* aLine,
       }
 #endif
       mSpaceManager->AddRectRegion(floater, fc->mRegion);
+      mLastFloaterY = fc->mRegion.y;
       fc = fc->Next();
     }
 #ifdef DEBUG
@@ -702,13 +693,9 @@ nsBlockReflowState::AddFloater(nsLineLayout& aLineLayout,
     nscoord dy = oy - mSpaceManagerY;
     mSpaceManager->Translate(-dx, -dy);
 
-    // Reflow the floater
-    mBlock->ReflowFloater(*this, aPlaceholder, fc->mCombinedArea,
-                          fc->mMargins, fc->mOffsets);
-
     // And then place it
     PRBool isLeftFloater;
-    PlaceFloater(fc, &isLeftFloater);
+    FlowAndPlaceFloater(fc, &isLeftFloater);    
 
     // Pass on updated available space to the current inline reflow engine
     GetAvailableSpace();
@@ -907,8 +894,8 @@ nsBlockReflowState::CanPlaceFloater(const nsRect& aFloaterRect,
 }
 
 void
-nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
-                                 PRBool* aIsLeftFloater)
+nsBlockReflowState::FlowAndPlaceFloater(nsFloaterCache* aFloaterCache,
+                                        PRBool* aIsLeftFloater)
 {
   // Save away the Y coordinate before placing the floater. We will
   // restore mY at the end after placing the floater. This is
@@ -916,9 +903,14 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
   // placement are for the floater only, not for any non-floating
   // content.
   nscoord saveY = mY;
+
+  // Grab the compatibility mode
+  nsCompatibility mode;
+  mPresContext->GetCompatibilityMode(&mode);
+
   nsIFrame* floater = aFloaterCache->mPlaceholder->GetOutOfFlowFrame();
 
-  // Get the type of floater
+  // Grab the floater's display information
   const nsStyleDisplay* floaterDisplay;
   const nsStylePosition* floaterPosition;
   floater->GetStyleData(eStyleStruct_Display,
@@ -926,59 +918,72 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
   floater->GetStyleData(eStyleStruct_Position,
                         (const nsStyleStruct*&)floaterPosition);
 
-  // See if the floater should clear any preceeding floaters...
-  if (NS_STYLE_CLEAR_NONE != floaterDisplay->mBreakType) {
-    ClearFloaters(mY, floaterDisplay->mBreakType);
-  }
-  else {
-    // Get the band of available space
-    GetAvailableSpace();
-  }
-
-  // Get the floaters bounding box and margin information
+  // This will hold the floater's geometry when we've found a place
+  // for it to live.
   nsRect region;
-  floater->GetRect(region);
 
-  // Adjust the floater size by its margin. That's the area that will
-  // impact the space manager.
-  region.width += aFloaterCache->mMargins.left + aFloaterCache->mMargins.right;
-  region.height += aFloaterCache->mMargins.top + aFloaterCache->mMargins.bottom;
+  // Advance mY to mLastFloaterY (if it's not past it already) to
+  // enforce 9.5.1 rule [2]; i.e., make sure that a float isn't
+  // ``above'' another float that preceded it in the flow.
+  mY = NS_MAX(mLastFloaterY, mY);
 
-  // Find a place to place the floater. The CSS2 spec doesn't want
-  // floaters overlapping each other or sticking out of the containing
-  // block if possible (CSS2 spec section 9.5.1, see the rule list).
-  NS_ASSERTION((NS_STYLE_FLOAT_LEFT == floaterDisplay->mFloats) ||
-               (NS_STYLE_FLOAT_RIGHT == floaterDisplay->mFloats),
-               "invalid float type");
-
-  // While there is not enough room for the floater, clear past other
-  // floaters until there is room (or the band is not impacted by a
-  // floater).
-  // 
-  // Note: The CSS2 spec says that floaters should be placed as high
-  // as possible.
-  //
-#ifdef FIX_BUG_37657
-  // Also note that in backwards compatibility mode, we skip this step
-  // for tables, since in old browsers, floating tables are horizontally
-  // stacked regardless of available space.  (See bug 43086 about
-  // tables vs. non-tables.)
-  nsCompatibility mode;
-  mPresContext->GetCompatibilityMode(&mode);
-  if ((eCompatibility_NavQuirks != mode) ||
-      (NS_STYLE_DISPLAY_TABLE != floaterDisplay->mDisplay)) {
-    while (!CanPlaceFloater(region, floaterDisplay->mFloats)) {
-      mY += mAvailSpaceRect.height;
+  while (1) {
+    // See if the floater should clear any preceeding floaters...
+    if (NS_STYLE_CLEAR_NONE != floaterDisplay->mBreakType) {
+      ClearFloaters(mY, floaterDisplay->mBreakType);
+    }
+    else {
+      // Get the band of available space
       GetAvailableSpace();
     }
-  }
-#else
-  while (!CanPlaceFloater(region, floaterDisplay->mFloats)) {
-    mY += mAvailSpaceRect.height;
-    GetAvailableSpace();
-  }
+
+    // Reflow the floater
+    mBlock->ReflowFloater(*this, aFloaterCache->mPlaceholder, aFloaterCache->mCombinedArea,
+                          aFloaterCache->mMargins, aFloaterCache->mOffsets,
+                          aFloaterCache->mMaxElementWidth);
+
+    // Get the floaters bounding box and margin information
+    floater->GetRect(region);
+
+#ifdef DEBUG
+    if (nsBlockFrame::gNoisyReflow) {
+      nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
+      printf("flowed floater: ");
+      nsFrame::ListTag(stdout, floater);
+      printf(" (%d,%d,%d,%d), max-element-width=%d\n",
+             region.x, region.y, region.width, region.height,
+             aFloaterCache->mMaxElementWidth);
+    }
 #endif
 
+    // Adjust the floater size by its margin. That's the area that will
+    // impact the space manager.
+    region.width += aFloaterCache->mMargins.left + aFloaterCache->mMargins.right;
+    region.height += aFloaterCache->mMargins.top + aFloaterCache->mMargins.bottom;
+
+    // Find a place to place the floater. The CSS2 spec doesn't want
+    // floaters overlapping each other or sticking out of the containing
+    // block if possible (CSS2 spec section 9.5.1, see the rule list).
+    NS_ASSERTION((NS_STYLE_FLOAT_LEFT == floaterDisplay->mFloats) ||
+                 (NS_STYLE_FLOAT_RIGHT == floaterDisplay->mFloats),
+                 "invalid float type");
+
+    // In backwards compatibility mode, we don't bother to see if a
+    // floated table can ``really'' fit: in old browsers, floating
+    // tables are horizontally stacked regardless of available space.
+    // (See bug 43086 about tables vs. non-tables.)
+    if ((eCompatibility_NavQuirks == mode) &&
+        (NS_STYLE_DISPLAY_TABLE == floaterDisplay->mDisplay))
+      break;
+
+    // Can the floater fit here?
+    if (CanPlaceFloater(region, floaterDisplay->mFloats))
+        break;
+
+    // Nope. Advance to the next band.
+    mY += mAvailSpaceRect.height;
+  }
+
   // Assign an x and y coordinate to the floater. Note that the x,y
   // coordinates are computed <b>relative to the translation in the
   // spacemanager</b> which means that the impacted region will be
@@ -1082,6 +1087,9 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
     nsBlockFrame::CombineRects(combinedArea, mFloaterCombinedArea);
   }
 
+  // Remember the y-coordinate of the floater we've just placed
+  mLastFloaterY = mY;
+
   // Now restore mY
   mY = saveY;
 
@@ -1091,7 +1099,7 @@ nsBlockReflowState::PlaceFloater(nsFloaterCache* aFloaterCache,
     floater->GetRect(r);
     nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
     printf("placed floater: ");
-    ((nsFrame*)floater)->ListTag(stdout);
+    nsFrame::ListTag(stdout, floater);
     printf(" %d,%d,%d,%d\n", r.x, r.y, r.width, r.height);
   }
 #endif
@@ -1114,12 +1122,10 @@ nsBlockReflowState::PlaceBelowCurrentLineFloaters(nsFloaterCacheList& aList)
         printf("\n");
       }
 #endif
-      mBlock->ReflowFloater(*this, fc->mPlaceholder, fc->mCombinedArea,
-                            fc->mMargins, fc->mOffsets);
 
       // Place the floater
       PRBool isLeftFloater;
-      PlaceFloater(fc, &isLeftFloater);
+      FlowAndPlaceFloater(fc, &isLeftFloater);
     }
     fc = fc->Next();
   }

layout/html/base/src/nsBlockReflowState.h

@@ -65,8 +65,8 @@ public:
 
   PRBool CanPlaceFloater(const nsRect& aFloaterRect, PRUint8 aFloats);
 
-  void PlaceFloater(nsFloaterCache* aFloaterCache,
-                    PRBool* aIsLeftFloater);
+  void FlowAndPlaceFloater(nsFloaterCache* aFloaterCache,
+                           PRBool* aIsLeftFloater);
 
   void PlaceBelowCurrentLineFloaters(nsFloaterCacheList& aFloaters);
 
@@ -177,6 +177,10 @@ public:
   // The combined area of all floaters placed so far
   nsRect mFloaterCombinedArea;
 
+  // The y-coordinate of the last floater placed. We keep this around
+  // to enforce 9.5.1 rule [2]
+  nscoord mLastFloaterY;
+
   // For unconstained-width reflow, we keep the right floaters
   // combined area stored seperately.
   PRBool mHaveRightFloaters;

layout/html/base/src/nsInlineFrame.cpp

@@ -355,20 +355,20 @@ NS_IMETHODIMP
 nsInlineFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
 {
   // The inline container frame does not handle the reflow
-  // request.  It passes it up to its parent container.  
+  // request.  It passes it up to its parent container.
 
   // If you don't already have dirty children,
   if (!(mState & NS_FRAME_HAS_DIRTY_CHILDREN)) {
     if (mParent) {
-      // Record that you are dirty and have dirty children    
+      // Record that you are dirty and have dirty children
       mState |= NS_FRAME_IS_DIRTY;
-      mState |= NS_FRAME_HAS_DIRTY_CHILDREN;      
+      mState |= NS_FRAME_HAS_DIRTY_CHILDREN; 
 
-      // Pass the reflow request up to the parent    
-      mParent->ReflowDirtyChild(aPresShell, (nsIFrame*) this);
+      // Pass the reflow request up to the parent
+      mParent->ReflowDirtyChild(aPresShell, this);
     }
     else {
-      NS_ASSERTION(0, "No parent to pass the reflow request up to.");
+      NS_ERROR("No parent to pass the reflow request up to.");
     }
   }
 

layout/html/base/src/nsLineBox.cpp

@@ -1097,6 +1097,7 @@ nsFloaterCache::nsFloaterCache()
     mMargins(0, 0, 0, 0),
     mOffsets(0, 0, 0, 0),
     mCombinedArea(0, 0, 0, 0),
+    mMaxElementWidth(NS_UNCONSTRAINEDSIZE),
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsFloaterCache);

layout/html/base/src/nsLineBox.h

@@ -67,6 +67,9 @@ public:
   // the containing block frame.
   nsRect mCombinedArea;
 
+  // The max element size for the floater.
+  nscoord mMaxElementWidth;
+
 protected:
   nsFloaterCache* mNext;