Fix treemap slice-dice mode.

For even depths, it was falling back to Math.min(rect.dx, rect.dy)
instead of always "dicing" (rect.dy).

d3.js

@@ -5092,7 +5092,7 @@
     function squarify(node) {
       var children = node.children;
       if (children && children.length) {
-        var rect = pad(node), row = [], remaining = children.slice(), child, best = Infinity, score, u = mode === "slice" ? rect.dx : mode === "dice" || mode === "slice-dice" && node.depth & 1 ? rect.dy : Math.min(rect.dx, rect.dy), n;
+        var rect = pad(node), row = [], remaining = children.slice(), child, best = Infinity, score, u = mode === "slice" ? rect.dx : mode === "dice" ? rect.dy : mode === "slice-dice" ? node.depth & 1 ? rect.dy : rect.dx : Math.min(rect.dx, rect.dy), n;
         scale(remaining, rect.dx * rect.dy / node.value);
         row.area = 0;
         while ((n = remaining.length) > 0) {

src/layout/treemap.js

@@ -34,7 +34,8 @@ d3.layout.treemap = function() {
           best = Infinity, // the best row score so far
           score, // the current row score
           u = mode === "slice" ? rect.dx
-            : mode === "dice" || mode === "slice-dice" && node.depth & 1 ? rect.dy
+            : mode === "dice" ? rect.dy
+            : mode === "slice-dice" ? node.depth & 1 ? rect.dy : rect.dx
             : Math.min(rect.dx, rect.dy), // initial orientation
           n;
       scale(remaining, rect.dx * rect.dy / node.value);

test/layout/treemap-test.js

@@ -154,6 +154,20 @@ suite.addBatch({
         {x: 0, y: 0, dx: 0, dy: 1},
         {x: 0, y: 0, dx: 1, dy: 1}
       ]);
+    },
+    "slice-dice": function(treemap) {
+      assert.deepEqual(treemap().size([100, 10]).mode("slice-dice").nodes({children: [
+        {children: [{value: 1}, {value: 1}]},
+        {children: [{value: 1}, {value: 1}]}
+      ]}).map(layout), [
+        {x: 0, y: 0, dx: 100, dy: 10},
+        {x: 50, y: 0, dx: 50, dy: 10},
+        {x: 50, y: 5, dx: 50, dy: 5},
+        {x: 50, y: 0, dx: 50, dy: 5},
+        {x: 0, y: 0, dx: 50, dy: 10},
+        {x: 0, y: 5, dx: 50, dy: 5},
+        {x: 0, y: 0, dx: 50, dy: 5}
+      ]);
     }
   }
 });