A Bug!

It's not often that I come across a real bug with Salesforce's apex or visualforce platform.  Most often there are limitations or shortcomings that you have to workaround.  Recently, I had to make an urgent change to a trigger and it's associated test class.  However, when I attempted to comment out a line in my test class, I got the following error in the editor when I tried to save:

java.lang.reflect.InvocationTargetException

When I attempted to make the same change in the developer console, I got another error:

 An unexpected error has occurred. 421011484-16071 (1420197083) for deploymentId=1drJ00000002FDxIAM If this persists, please contact customer support.

Fortunately, I was able to still deploy my code without the test class change but I opened a case anyway and after waiting a few days for a reply, was told that it was a known issue.  The instructions from developer support were:

• Please clear Test results and try to save the code:
• From Setup, click Develop | Apex Test Execution |View Test History | Clear test results. 

However, even before I did these actions, I tried to update the test class again and surprise!  no errors. So, something fishy is going on... Support wants to close the case but I'm inquiring for additional details.  Will keep you posted.

**Update Nov 13**

Salesforce has responded and indicated that it was a bug but has been fixed.  Details here: https://success.salesforce.com/issues_view?id=a1p30000000T17j