Fix assert in dart:math/Rectangle.

sdk/lib/math/rectangle.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 part of dart.math;
 
 /**
  * A base class for representing two-dimensional axis-aligned rectangles.
  *
  * This rectangle uses a left-handed Cartesian coordinate system, with x
  * directed to the right and y directed down, as per the convention in 2D
@@ skipping 130 matching lines @@
    * with x-coordinate between `left` and `left + width`, and
    * with y-coordinate between `top` and `top + height`, both inclusive.
    *
    * The `width` and `height` should be non-negative.
    * If `width` or `height` are negative, they are clamped to zero.
    *
    * If `width` and `height` are zero, the "rectangle" comprises only the single
    * point `(left, top)`.
    */
   const Rectangle(this.left, this.top, T width, T height)
-      : this.width = (width >= 0) ? width : -width * 0,  // Inline _clampToZero.
-        this.height = (height >= 0) ? height : -height * 0;
+      : this.width = (width < 0) ? -width * 0 : width,  // Inline _clampToZero.
+        this.height = (height < 0) ?  -height * 0 : height;
 
   /**
    * Create a rectangle spanned by the points [a] and [b];
    *
    * The rectangle contains the points
    * with x-coordinate between `a.x` and `b.x`, and
    * with y-coordinate between `a.y` and `b.y`, both inclusive.
    *
    * If the distance between `a.x` and `b.x` is not representable
    * (which can happen if one or both is a double),
@@ skipping 39 matching lines @@
    * with x-coordinate between `left` and `left + width`, and
    * with y-coordinate between `top` and `top + height`, both inclusive.
    *
    * The `width` and `height` should be non-negative.
    * If `width` or `height` are negative, they are clamped to zero.
    *
    * If `width` and `height` are zero, the "rectangle" comprises only the single
    * point `(left, top)`.
    */
   MutableRectangle(this.left, this.top, T width, T height)
-      : this._width = (width >= 0) ? width : _clampToZero(width),
-        this._height = (height >= 0) ? height : _clampToZero(height);
+      : this._width = (width < 0) ? _clampToZero(width) : width,
+        this._height = (height < 0) ? _clampToZero(height) : height;
 
   /**
    * Create a mutable rectangle spanned by the points [a] and [b];
    *
    * The rectangle contains the points
    * with x-coordinate between `a.x` and `b.x`, and
    * with y-coordinate between `a.y` and `b.y`, both inclusive.
    *
    * If the distance between `a.x` and `b.x` is not representable
    * (which can happen if one or both is a double),
@@ skipping 43 matching lines @@
 
 /**
  * Converts a negative [int] or [double] to a zero-value of the same type.
  *
  * Returns `0` if value is int, `0.0` if value is double.
  */
 num _clampToZero(num value) {
   assert(value < 0);
   return -value * 0;
 }