Program: 18790
Project: 18790
Buggy source:
/** 
 * Updates the initial assignment to a collapsible property at global scope by changing it to a variable declaration (e.g. a.b = 1 -> var a$b = 1). The property's value may either be a primitive or an object literal or function whose properties aren't collapsible.
 * @param alias The flattened property name (e.g. "a$b")
 * @param refName The name for the reference being updated.
 * @param ref An object containing information about the assignment gettingupdated
 */
private void updateSimpleDeclaration(String alias,Name refName,Ref ref){
  Node rvalue=ref.node.getNext();
  Node parent=ref.node.getParent();
  Node gramps=parent.getParent();
  Node greatGramps=gramps.getParent();
  Node greatGreatGramps=greatGramps.getParent();
  if (rvalue != null && rvalue.getType() == Token.FUNCTION) {
    checkForHosedThisReferences(rvalue,refName.docInfo,refName);
  }
  Node nameNode=NodeUtil.newName(compiler.getCodingConvention(),alias,gramps.getFirstChild(),refName.fullName());
  NodeUtil.copyNameAnnotations(ref.node.getLastChild(),nameNode);
  if (gramps.getType() == Token.EXPR_RESULT) {
    parent.removeChild(rvalue);
    nameNode.addChildToFront(rvalue);
    Node varNode=new Node(Token.VAR,nameNode);
    greatGramps.replaceChild(gramps,varNode);
  }
 else {
    Preconditions.checkNotNull(ref.getTwin());
    Node current=gramps;
    Node currentParent=gramps.getParent();
    for (; currentParent.getType() != Token.SCRIPT && currentParent.getType() != Token.BLOCK; current=currentParent, currentParent=currentParent.getParent()) {
    }
    Node stubVar=new Node(Token.VAR,nameNode.cloneTree()).copyInformationFrom(nameNode);
    currentParent.addChildBefore(stubVar,current);
    parent.replaceChild(ref.node,nameNode);
  }
  compiler.reportCodeChange();
}

Fixed version (ground truth):
/** 
 * Updates the initial assignment to a collapsible property at global scope by changing it to a variable declaration (e.g. a.b = 1 -> var a$b = 1). The property's value may either be a primitive or an object literal or function whose properties aren't collapsible.
 * @param alias The flattened property name (e.g. "a$b")
 * @param refName The name for the reference being updated.
 * @param ref An object containing information about the assignment gettingupdated
 */
private void updateSimpleDeclaration(String alias,Name refName,Ref ref){
  Node rvalue=ref.node.getNext();
  Node parent=ref.node.getParent();
  Node gramps=parent.getParent();
  Node greatGramps=gramps.getParent();
  Node greatGreatGramps=greatGramps.getParent();
  if (rvalue != null && rvalue.getType() == Token.FUNCTION) {
    checkForHosedThisReferences(rvalue,refName.docInfo,refName);
  }
  Node nameNode=NodeUtil.newName(compiler.getCodingConvention(),alias,gramps.getFirstChild(),refName.getFullName());
  NodeUtil.copyNameAnnotations(ref.node.getLastChild(),nameNode);
  if (gramps.getType() == Token.EXPR_RESULT) {
    parent.removeChild(rvalue);
    nameNode.addChildToFront(rvalue);
    Node varNode=new Node(Token.VAR,nameNode);
    greatGramps.replaceChild(gramps,varNode);
  }
 else {
    Preconditions.checkNotNull(ref.getTwin());
    Node current=gramps;
    Node currentParent=gramps.getParent();
    for (; currentParent.getType() != Token.SCRIPT && currentParent.getType() != Token.BLOCK; current=currentParent, currentParent=currentParent.getParent()) {
    }
    Node stubVar=new Node(Token.VAR,nameNode.cloneTree()).copyInformationFrom(nameNode);
    currentParent.addChildBefore(stubVar,current);
    parent.replaceChild(ref.node,nameNode);
  }
  compiler.reportCodeChange();
}