Bug 46043. Be sure to clear m[Left|Right]Floaters when 0 == mCount. r=buster

layout/generic/nsBlockBandData.cpp

@@ -145,6 +145,8 @@ nsBlockBandData::ComputeAvailSpaceRect()
     mAvailSpace.y = 0;
     mAvailSpace.width = 0;
     mAvailSpace.height = 0;
+    mLeftFloaters = 0;
+    mRightFloaters = 0;
     return;
   }
 

layout/html/base/src/nsBlockBandData.cpp

@@ -145,6 +145,8 @@ nsBlockBandData::ComputeAvailSpaceRect()
     mAvailSpace.y = 0;
     mAvailSpace.width = 0;
     mAvailSpace.height = 0;
+    mLeftFloaters = 0;
+    mRightFloaters = 0;
     return;
   }