Fix spinning_mixed.dart, and resulting yak shave.

sky/sdk/lib/rendering/box.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 
 import 'package:vector_math/vector_math.dart';
 
 import '../base/debug.dart';
@@ skipping 1030 matching lines @@
   }
 
   Size _sizeForConstraints(BoxConstraints innerConstraints) {
     // If there's no image, we can't size ourselves automatically
     if (_image == null) {
       double width = requestedSize.width == null ? 0.0 : requestedSize.width;
       double height = requestedSize.height == null ? 0.0 : requestedSize.height;
       return constraints.constrain(new Size(width, height));
     }
 
-    // If neither height nor width are specified, use inherent image dimensions
-    // If only one dimension is specified, adjust the other dimension to
-    // maintain the aspect ratio
-    if (requestedSize.width == null) {
-      if (requestedSize.height == null) {
-        return constraints.constrain(new Size(_image.width.toDouble(), _image.height.toDouble()));
-      } else {
+    if (!innerConstraints.isTight) {
+      // If neither height nor width are specified, use inherent image
+      // dimensions. If only one dimension is specified, adjust the
+      // other dimension to maintain the aspect ratio. In both cases,
+      // constrain dimensions first, otherwise we end up losing the
+      // ratio after constraining.
+      if (requestedSize.width == null) {
+        if (requestedSize.height == null) {
+          // autosize
+          double maxHeight = math.min(math.max(constraints.minHeight, constraints.maxHeight), _image.height.toDouble());

[abarth-chromium, 2015/07/07 00:11:15]

Is this not just constraints.constrainHeight ?

+          double width = math.min(math.max(constraints.minWidth, constraints.maxWidth), _image.width.toDouble());

[abarth-chromium, 2015/07/07 00:11:15]

Ditto

+          double ratio = _image.height / _image.width;
+          double height = width * ratio;
+          if (height > maxHeight) {
+            height = maxHeight;
+            width = maxHeight / ratio;
+          }
+          return constraints.constrain(new Size(width, height));
+        }
+        // determine width from height
         double width = requestedSize.height * _image.width / _image.height;
         return constraints.constrain(new Size(width, requestedSize.height));
       }
-    } else if (requestedSize.height == null) {
-      double height = requestedSize.width * _image.height / _image.width;
-      return constraints.constrain(new Size(requestedSize.width, height));
-    } else {
-      return constraints.constrain(requestedSize);
+      if (requestedSize.height == null) {
+        // determine height from width
+        double height = requestedSize.width * _image.height / _image.width;
+        return constraints.constrain(new Size(requestedSize.width, height));
+      }
     }
+    return constraints.constrain(requestedSize);
   }
 
   double getMinIntrinsicWidth(BoxConstraints constraints) {
     if (requestedSize.width == null && requestedSize.height == null)
       return constraints.constrainWidth(0.0);
     return _sizeForConstraints(constraints).width;
   }
 
   double getMaxIntrinsicWidth(BoxConstraints constraints) {
     return _sizeForConstraints(constraints).width;
@@ skipping 344 matching lines @@
 
   void defaultPaint(PaintingCanvas canvas, Offset offset) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position + offset);
       child = child.parentData.nextSibling;
     }
   }
 }