modules/controls/src/main/java/com/sun/javafx/scene/control/skin/TreeTableViewSkin.java

*** 1,7 ****
  /*
!  * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 349,364 ****
          double headerWidth = headerTextWidth + headerGraphicWidth + 10 + header.snappedLeftInset() + header.snappedRightInset();
          maxWidth = Math.max(maxWidth, headerWidth);
  
          // RT-23486
          maxWidth += padding;
!         if(treeTableView.getColumnResizePolicy() == TreeTableView.CONSTRAINED_RESIZE_POLICY) {
!             maxWidth = Math.max(maxWidth, col.getWidth());
          }
  
          col.impl_setWidth(maxWidth);
      }
  
      /** {@inheritDoc} */
      @Override public int getItemCount() {
          return treeTableView.getExpandedItemCount();
      }
--- 349,375 ----
          double headerWidth = headerTextWidth + headerGraphicWidth + 10 + header.snappedLeftInset() + header.snappedRightInset();
          maxWidth = Math.max(maxWidth, headerWidth);
  
          // RT-23486
          maxWidth += padding;
!         if (treeTableView.getColumnResizePolicy() == TreeTableView.CONSTRAINED_RESIZE_POLICY && treeTableView.getWidth() > 0) {
! 
!             if (maxWidth > tc.getMaxWidth()) {
!                 maxWidth = tc.getMaxWidth();
!             }
! 
!             int size = tc.getColumns().size();
!             if (size > 0) {
!                 resizeColumnToFitContent(tc.getColumns().get(size - 1), maxRows);
!                 return;
              }
  
+             resizeColumn(tc, Math.round(maxWidth - tc.getWidth()));
+         } else {
              col.impl_setWidth(maxWidth);
          }
+     }
  
      /** {@inheritDoc} */
      @Override public int getItemCount() {
          return treeTableView.getExpandedItemCount();
      }