diff --git a/core/keyboard_nav/ast_node.js b/core/keyboard_nav/ast_node.js
index 158407d7a..54778818f 100644
--- a/core/keyboard_nav/ast_node.js
+++ b/core/keyboard_nav/ast_node.js
@@ -313,8 +313,8 @@ Blockly.ASTNode.prototype.findNextForField_ = function() {
   var block = location.getSourceBlock();
   var curIdx = block.inputList.indexOf(input);
   var fieldIdx = input.fieldRow.indexOf(location) + 1;
-  for (var i = curIdx, input; input = block.inputList[i]; i++) {
-    var fieldRow = input.fieldRow;
+  for (var i = curIdx, newInput; newInput = block.inputList[i]; i++) {
+    var fieldRow = newInput.fieldRow;
     while (fieldIdx < fieldRow.length) {
       if (fieldRow[fieldIdx].EDITABLE) {
         return Blockly.ASTNode.createFieldNode(fieldRow[fieldIdx]);
@@ -322,8 +322,8 @@ Blockly.ASTNode.prototype.findNextForField_ = function() {
       fieldIdx++;
     }
     fieldIdx = 0;
-    if (input.connection) {
-      return Blockly.ASTNode.createInputNode(input);
+    if (newInput.connection) {
+      return Blockly.ASTNode.createInputNode(newInput);
     }
   }
   return null;
@@ -438,12 +438,15 @@ Blockly.ASTNode.prototype.findTopASTNodeForBlock_ = function(block) {
 /**
  * Get the AST node pointing to the input that the block is nested under or if
  * the block is not nested then get the stack AST node.
- * @param {!Blockly.Block} block The source block of the current location.
+ * @param {Blockly.Block} block The source block of the current location.
  * @return {Blockly.ASTNode} The AST node pointing to the input connection or
  *     the top block of the stack this block is in.
  * @private
  */
 Blockly.ASTNode.prototype.getOutAstNodeForBlock_ = function(block) {
+  if (!block) {
+    return null;
+  }
   var topBlock = null;
   // If the block doesn't have a previous connection then it is the top of the
   // substack.
@@ -467,7 +470,7 @@ Blockly.ASTNode.prototype.getOutAstNodeForBlock_ = function(block) {
 
 /**
  * Find the first editable field or input with a connection on a given block.
- * @param {!Blockly.BlockSvg} block The source block of the current location.
+ * @param {!Blockly.Block} block The source block of the current location.
  * @return {Blockly.ASTNode} An AST node pointing to the first field or input.
  * Null if there are no editable fields or inputs with connections on the block.
  * @private
@@ -568,6 +571,7 @@ Blockly.ASTNode.prototype.in = function() {
       return this.findTopASTNodeForBlock_(block);
 
     case Blockly.ASTNode.types.BLOCK:
+      var block = /** @type {!Blockly.Block} */ (this.location_);
       return this.findFirstFieldOrInput_(this.location_);
 
     case Blockly.ASTNode.types.INPUT:
diff --git a/core/keyboard_nav/cursor.js b/core/keyboard_nav/cursor.js
index 9bfd4a4a6..5b1e1d3ce 100644
--- a/core/keyboard_nav/cursor.js
+++ b/core/keyboard_nav/cursor.js
@@ -184,7 +184,7 @@ Blockly.Cursor.prototype.out = function() {
   }
   var newNode = curNode.out();
   
-  if (newNode.getType() === Blockly.ASTNode.types.BLOCK) {
+  if (newNode && newNode.getType() === Blockly.ASTNode.types.BLOCK) {
     newNode = newNode.prev();
   }
 
diff --git a/core/keyboard_nav/cursor_svg.js b/core/keyboard_nav/cursor_svg.js
index 1bf28459c..efddcfd16 100644
--- a/core/keyboard_nav/cursor_svg.js
+++ b/core/keyboard_nav/cursor_svg.js
@@ -347,9 +347,9 @@ Blockly.CursorSvg.prototype.showCurrent_ = function() {
 /**
  * Position the cursor for a block.
  * Displays an outline of the top half of a rectangle around a block.
- * @param {!number} width The width of the block.
- * @param {!number} cursorOffset The extra padding for around the block.
- * @param {!number} cursorHeight The height of the cursor.
+ * @param {number} width The width of the block.
+ * @param {number} cursorOffset The extra padding for around the block.
+ * @param {number} cursorHeight The height of the cursor.
  */
 Blockly.CursorSvg.prototype.positionBlock_ = function(width, cursorOffset, cursorHeight) {
   var cursorPath = Blockly.utils.svgPaths.moveBy(-1 * cursorOffset, cursorHeight) +
@@ -377,9 +377,9 @@ Blockly.CursorSvg.prototype.positionInput_ = function(connection) {
 /**
  * Move and show the cursor at the specified coordinate in workspace units.
  * Displays a horizontal line.
- * @param {!number} x The new x, in workspace units.
- * @param {!number} y The new y, in workspace units.
- * @param {!number} width The new width, in workspace units.
+ * @param {number} x The new x, in workspace units.
+ * @param {number} y The new y, in workspace units.
+ * @param {number} width The new width, in workspace units.
  * @private
  */
 Blockly.CursorSvg.prototype.positionLine_ = function(x, y, width) {
@@ -391,8 +391,8 @@ Blockly.CursorSvg.prototype.positionLine_ = function(x, y, width) {
 /**
  * Position the cursor for an output connection.
  * Displays a puzzle outline and the top and bottom path.
- * @param {!number} width The width of the block.
- * @param {!number} height The height of the block.
+ * @param {number} width The width of the block.
+ * @param {number} height The height of the block.
  * @private
  */
 Blockly.CursorSvg.prototype.positionOutput_ = function(width, height) {
@@ -409,9 +409,9 @@ Blockly.CursorSvg.prototype.positionOutput_ = function(width, height) {
  * Position the cursor for a previous connection.
  * Displays a half rectangle with a notch in the top to represent the previous
  * conenction.
- * @param {!number} width The width of the block.
- * @param {!number} cursorOffset The offset of the cursor from around the block.
- * @param {!number} cursorHeight The height of the cursor.
+ * @param {number} width The width of the block.
+ * @param {number} cursorOffset The offset of the cursor from around the block.
+ * @param {number} cursorHeight The height of the cursor.
  * @private
  */
 Blockly.CursorSvg.prototype.positionPrevious_ = function(width, cursorOffset, cursorHeight) {
@@ -428,10 +428,10 @@ Blockly.CursorSvg.prototype.positionPrevious_ = function(width, cursorOffset, cu
 /**
  * Move and show the cursor at the specified coordinate in workspace units.
  * Displays a filled in rectangle.
- * @param {!number} x The new x, in workspace units.
- * @param {!number} y The new y, in workspace units.
- * @param {!number} width The new width, in workspace units.
- * @param {!number} height The new height, in workspace units.
+ * @param {number} x The new x, in workspace units.
+ * @param {number} y The new y, in workspace units.
+ * @param {number} width The new width, in workspace units.
+ * @param {number} height The new height, in workspace units.
  * @private
  */
 Blockly.CursorSvg.prototype.positionRect_ = function(x, y, width, height) {
@@ -459,8 +459,10 @@ Blockly.CursorSvg.prototype.hide = function() {
  */
 Blockly.CursorSvg.prototype.draw = function(curNode) {
   if (!curNode) {
+    this.hide();
     return;
   }
+
   if (curNode.getType() === Blockly.ASTNode.types.BLOCK) {
     var block = /** @type {Blockly.BlockSvg} */ (curNode.getLocation());
     this.showWithBlockPrevOutput_(block);
diff --git a/core/keyboard_nav/flyout_cursor.js b/core/keyboard_nav/flyout_cursor.js
index a9e62ea35..428dce97c 100644
--- a/core/keyboard_nav/flyout_cursor.js
+++ b/core/keyboard_nav/flyout_cursor.js
@@ -49,18 +49,16 @@ Blockly.utils.object.inherits(Blockly.FlyoutCursor, Blockly.Cursor);
  * @override
  */
 Blockly.FlyoutCursor.prototype.next = function() {
-  if (!this.isMarker_) {
-    var curNode = this.getCurNode();
-    if (!curNode) {
-      return null;
-    }
-    var newNode = curNode.next();
-
-    if (newNode) {
-      this.setLocation(newNode);
-    }
-    return newNode;
+  var curNode = this.getCurNode();
+  if (!curNode) {
+    return null;
   }
+  var newNode = curNode.next();
+
+  if (newNode) {
+    this.setLocation(newNode);
+  }
+  return newNode;
 };
 
 /**
@@ -79,18 +77,16 @@ Blockly.FlyoutCursor.prototype.in = function() {
  * @override
  */
 Blockly.FlyoutCursor.prototype.prev = function() {
-  if (!this.isMarker_) {
-    var curNode = this.getCurNode();
-    if (!curNode) {
-      return null;
-    }
-    var newNode = curNode.prev();
-    
-    if (newNode) {
-      this.setLocation(newNode);
-    }
-    return newNode;
+  var curNode = this.getCurNode();
+  if (!curNode) {
+    return null;
   }
+  var newNode = curNode.prev();
+
+  if (newNode) {
+    this.setLocation(newNode);
+  }
+  return newNode;
 };
 
 /**
diff --git a/core/keyboard_nav/key_map.js b/core/keyboard_nav/key_map.js
index c53d02291..12c90cdba 100644
--- a/core/keyboard_nav/key_map.js
+++ b/core/keyboard_nav/key_map.js
@@ -99,7 +99,7 @@ Blockly.user.keyMap.getActionByKeyCode = function(keyCode) {
  * Get the serialized key that corresponds to the action.
  * @param {!Blockly.Action} action The action for which we want to get
  *     the key.
- * @return {string} The serialized key or null if the action does not have
+ * @return {?string} The serialized key or null if the action does not have
  *     a key mapping.
  * @package
  */
diff --git a/core/keyboard_nav/navigation.js b/core/keyboard_nav/navigation.js
index 429c99cdc..5c724b3ab 100644
--- a/core/keyboard_nav/navigation.js
+++ b/core/keyboard_nav/navigation.js
@@ -264,7 +264,7 @@ Blockly.navigation.focusFlyout_ = function() {
   }
 
   if (flyout && flyout.getWorkspace()) {
-    var topBlocks = flyout.getWorkspace().getTopBlocks();
+    var topBlocks = flyout.getWorkspace().getTopBlocks(true);
     if (topBlocks.length > 0) {
       topBlock = topBlocks[0];
       var astNode = Blockly.ASTNode.createStackNode(topBlock);
@@ -665,7 +665,7 @@ Blockly.navigation.focusWorkspace_ = function() {
   Blockly.hideChaff();
   var cursor = Blockly.getMainWorkspace().getCursor();
   var reset = Blockly.getMainWorkspace().getToolbox() ? true : false;
-  var topBlocks = Blockly.getMainWorkspace().getTopBlocks();
+  var topBlocks = Blockly.getMainWorkspace().getTopBlocks(true);
 
   Blockly.navigation.resetFlyout_(reset);
   Blockly.navigation.currentState_ = Blockly.navigation.STATE_WS;
@@ -717,9 +717,9 @@ Blockly.navigation.getSourceBlock_ = function(node) {
     return null;
   }
   if (node.getType() === Blockly.ASTNode.types.BLOCK) {
-    return node.getLocation();
+    return /** @type {Blockly.Block} */ (node.getLocation());
   } else if (node.getType() === Blockly.ASTNode.types.STACK) {
-    return node.getLocation();
+    return /** @type {Blockly.Block} */ (node.getLocation());
   } else if (node.getType() === Blockly.ASTNode.types.WORKSPACE) {
     return null;
   } else {
@@ -756,7 +756,7 @@ Blockly.navigation.moveCursorOnBlockDelete = function(deletedBlock) {
       }
     // If the cursor is on a block whose parent is being deleted, move the
     // cursor to the workspace.
-    } else if (deletedBlock.getChildren().indexOf(block) > -1) {
+    } else if (deletedBlock.getChildren(false).indexOf(block) > -1) {
       cursor.setLocation(Blockly.ASTNode.createWorkspaceNode(block.workspace,
           block.getRelativeToSurfaceXY()));
     }