Describe the problem in greater detail here, summarizing the behavior.
The code path that tries to adjust for DST difference will never break out of the loop if the Date.getDate() is NaN. This should probably check for isNaN() first and either throw an Exeption or fail silently and log a message if in dev mode.
Steps to reproduce the problem:
Execute the following in any ExtJS application:
The result that was expected:
Maybe an Exception? or nothing?
The result that occurs instead:
Browser locks up, eventually you get the slow script warning and can stop it