Follow-up to 26c725 to work on more browsers.

Windows Safari (eg) seems to apply the "uncheck existing radios when new radios
are created" even earlier than other browsers, so save values earlier.

packages/spark/spark.js

@@ -583,6 +583,18 @@ Spark.renderToRange = function (range, htmlFunc) {
     notes.originalRange = landmarkRange;
   });
 
+  // Once we render the new fragment, as soon as it is placed into the DOM (even
+  // temporarily), if any radio buttons in the new framgent are checked, any
+  // radio buttons with the same name in the entire document will be unchecked
+  // (since only one radio button of a given name can be checked at a time). So
+  // we save the current checked value of all radio buttons in an expando.
+  var radios = DomUtils.findAllClipped(
+    range.containerNode(), 'input[type=radio]',
+    range.firstNode(), range.lastNode());
+  _.each(radios, function (node) {
+    node._currentChecked = [!!node.checked];
+  });
+
   var frag = renderer.materialize(htmlFunc);
 
   DomUtils.wrapFragmentForContainer(frag, range.containerNode());
@@ -621,18 +633,6 @@ Spark.renderToRange = function (range, htmlFunc) {
 
   pc.addRoot(Spark._globalPreserves, range, tempRange);
 
-  // computePreservations is going to insert 'tempRange' into the DOM
-  // temporarily. If any radio buttons in 'tempRange' are checked, this will
-  // instantly uncheck any radio buttons with the same name in 'range' (since
-  // only one radio button of a given name can be checked at a time). So we save
-  // the current checked value of all radio buttons in an expando.
-  var radios = DomUtils.findAllClipped(
-    range.containerNode(), 'input[type=radio]',
-    range.firstNode(), range.lastNode());
-  _.each(radios, function (node) {
-    node._currentChecked = [!!node.checked];
-  });
-
   // compute preservations (must do this before destroying tempRange)
   var preservations = pc.computePreservations(range, tempRange);