Add list of ids to create/delete events for robustness.

core/block.js

@@ -187,10 +187,6 @@ Blockly.Block.prototype.dispose = function(healStack) {
   // well as corruption of the connection database.  Therefore we must
   // methodically step through the blocks and carefully disassemble them.
 
-  if (Blockly.selected == this) {
-    Blockly.selected = null;
-  }
-
   // First, dispose of all my children.
   for (var i = this.childBlocks_.length - 1; i >= 0; i--) {
     this.childBlocks_[i].dispose(false);

core/block_svg.js

@@ -935,6 +935,7 @@ Blockly.BlockSvg.prototype.dispose = function(healStack, animate) {
   Blockly.Field.startCache();
   // If this block is being dragged, unlink the mouse events.
   if (Blockly.selected == this) {
+    this.unselect();
     Blockly.terminateDrag_();
   }
   // If this block has a context menu open, close it.

core/events.js

@@ -224,6 +224,21 @@ Blockly.Events.setGroup = function(state) {
   }
 };
 
+/**
+ * Compute a list of the IDs of the specified block and all its descendants.
+ * @param {!Blockly.Block} block The root block.
+ * @return {!Array.<string>} List of block IDs.
+ * @private
+ */
+Blockly.Events.getDescendantIds_ = function(block) {
+  var ids = [];
+  var descendants = block.getDescendants();
+  for (var i = 0, descendant; descendant = descendants[i]; i++) {
+    ids[i] = descendant.id;
+  }
+  return ids;
+};
+
 /**
  * Abstract class for an event.
  * @param {!Blockly.Block} block The block.
@@ -277,6 +292,7 @@ Blockly.Events.Abstract.prototype.run = function(forward) {
 Blockly.Events.Create = function(block) {
   Blockly.Events.Create.superClass_.constructor.call(this, block);
   this.xml = Blockly.Xml.blockToDomWithXY(block);
+  this.ids = Blockly.Events.getDescendantIds_(block);
 };
 goog.inherits(Blockly.Events.Create, Blockly.Events.Abstract);
 
@@ -293,6 +309,7 @@ Blockly.Events.Create.prototype.type = Blockly.Events.CREATE;
 Blockly.Events.Create.prototype.toJson = function() {
   var json = Blockly.Events.Create.superClass_.toJson.call(this);
   json['xml'] = Blockly.Xml.domToText(this.xml);
+  json['ids'] = this.ids;
   return json;
 };
 
@@ -307,11 +324,14 @@ Blockly.Events.Create.prototype.run = function(forward) {
     xml.appendChild(this.xml);
     Blockly.Xml.domToWorkspace(workspace, xml);
   } else {
-    var block = Blockly.Block.getById(this.blockId);
-    if (block) {
-      block.dispose(false, true);
-    } else {
-      console.warn("Can't delete non-existant block: " + this.blockId);
+    for (var i = 0, id; id = this.ids[i]; i++) {
+      var block = Blockly.Block.getById(id);
+      if (block) {
+        block.dispose(false, true);
+      } else if (id == this.blockId) {
+        // Only complain about root-level block.
+        console.warn("Can't uncreate non-existant block: " + id);
+      }
     }
   }
 };
@@ -328,6 +348,7 @@ Blockly.Events.Delete = function(block) {
   }
   Blockly.Events.Delete.superClass_.constructor.call(this, block);
   this.oldXml = Blockly.Xml.blockToDomWithXY(block);
+  this.ids = Blockly.Events.getDescendantIds_(block);
 };
 goog.inherits(Blockly.Events.Delete, Blockly.Events.Abstract);
 
@@ -337,17 +358,30 @@ goog.inherits(Blockly.Events.Delete, Blockly.Events.Abstract);
  */
 Blockly.Events.Delete.prototype.type = Blockly.Events.DELETE;
 
+/**
+ * Encode the event as JSON.
+ * @return {!Object} JSON representation.
+ */
+Blockly.Events.Delete.prototype.toJson = function() {
+  var json = Blockly.Events.Delete.superClass_.toJson.call(this);
+  json['ids'] = this.ids;
+  return json;
+};
+
 /**
  * Run a deletion event.
  * @param {boolean} forward True if run forward, false if run backward (undo).
  */
 Blockly.Events.Delete.prototype.run = function(forward) {
   if (forward) {
-    var block = Blockly.Block.getById(this.blockId);
-    if (block) {
-      block.dispose(false, true);
-    } else {
-      console.warn("Can't delete non-existant block: " + this.blockId);
+    for (var i = 0, id; id = this.ids[i]; i++) {
+      var block = Blockly.Block.getById(id);
+      if (block) {
+        block.dispose(false, true);
+      } else if (id == this.blockId) {
+        // Only complain about root-level block.
+        console.warn("Can't delete non-existant block: " + id);
+      }
     }
   } else {
     var workspace = Blockly.Workspace.getById(this.workspaceId);