Fix Block intrinsic functions (#3286)

* Fix Block intrinsic functions

* Update block_test.dart

Fix the test per travis

packages/flutter/lib/src/rendering/block.dart

@@ -157,7 +157,7 @@ class RenderBlock extends RenderBox
     while (child != null) {
       switch (mainAxis) {
         case Axis.horizontal:
-          extent += child.getMinIntrinsicWidth(innerConstraints);
+          extent += child.getMaxIntrinsicWidth(innerConstraints);
           break;
         case Axis.vertical:
           extent += child.getMinIntrinsicHeight(innerConstraints);
@@ -206,7 +206,7 @@ class RenderBlock extends RenderBox
       case Axis.horizontal:
         return _getIntrinsicCrossAxis(
           constraints,
-          (RenderBox child, BoxConstraints innerConstraints) => child.getMinIntrinsicWidth(innerConstraints),
+          (RenderBox child, BoxConstraints innerConstraints) => child.getMinIntrinsicHeight(innerConstraints),
           constraints.constrainHeight
         );
       case Axis.vertical:
@@ -221,7 +221,7 @@ class RenderBlock extends RenderBox
       case Axis.horizontal:
         return _getIntrinsicCrossAxis(
           constraints,
-          (RenderBox child, BoxConstraints innerConstraints) => child.getMaxIntrinsicWidth(innerConstraints),
+          (RenderBox child, BoxConstraints innerConstraints) => child.getMaxIntrinsicHeight(innerConstraints),
           constraints.constrainHeight
         );
       case Axis.vertical:

packages/flutter/test/rendering/block_test.dart

@@ -30,11 +30,15 @@ void main() {
     expect(paragraph.getMaxIntrinsicHeight(unconstrained), equals(oneLineTextHeight));
     expect(paragraph.getMaxIntrinsicHeight(constrained), equals(twoLinesTextHeight));
 
-    RenderBox testBlock = new RenderBlock(
+    // test setup
+    RenderBlock testBlock = new RenderBlock(
       children: <RenderBox>[
         paragraph,
       ]
     );
+    final BoxConstraints empty = new BoxConstraints.tight(Size.zero);
+
+    // vertical block
     expect(testBlock.getMinIntrinsicWidth(unconstrained), equals(wrappedTextWidth));
     expect(testBlock.getMinIntrinsicWidth(constrained), equals(wrappedTextWidth));
     expect(testBlock.getMaxIntrinsicWidth(unconstrained), equals(textWidth));
@@ -43,8 +47,21 @@ void main() {
     expect(testBlock.getMinIntrinsicHeight(constrained), equals(twoLinesTextHeight));
     expect(testBlock.getMaxIntrinsicHeight(unconstrained), equals(oneLineTextHeight));
     expect(testBlock.getMaxIntrinsicHeight(constrained), equals(twoLinesTextHeight));
+    expect(testBlock.getMinIntrinsicWidth(empty), equals(0.0));
+    expect(testBlock.getMaxIntrinsicWidth(empty), equals(0.0));
+    expect(testBlock.getMinIntrinsicHeight(empty), equals(0.0));
+    expect(testBlock.getMaxIntrinsicHeight(empty), equals(0.0));
 
-    final BoxConstraints empty = new BoxConstraints.tight(Size.zero);
+    // horizontal block
+    testBlock.mainAxis = Axis.horizontal;
+    expect(testBlock.getMinIntrinsicWidth(unconstrained), equals(textWidth));
+    expect(testBlock.getMinIntrinsicWidth(constrained), equals(constrained.maxWidth));
+    expect(testBlock.getMaxIntrinsicWidth(unconstrained), equals(textWidth));
+    expect(testBlock.getMaxIntrinsicWidth(constrained), equals(constrained.maxWidth));
+    expect(testBlock.getMinIntrinsicHeight(unconstrained), equals(oneLineTextHeight));
+    expect(testBlock.getMinIntrinsicHeight(constrained), equals(oneLineTextHeight));
+    expect(testBlock.getMaxIntrinsicHeight(unconstrained), equals(oneLineTextHeight));
+    expect(testBlock.getMaxIntrinsicHeight(constrained), equals(oneLineTextHeight));
     expect(testBlock.getMinIntrinsicWidth(empty), equals(0.0));
     expect(testBlock.getMaxIntrinsicWidth(empty), equals(0.0));
     expect(testBlock.getMinIntrinsicHeight(empty), equals(0.0));