[gui] Renaming a method to something that would match a keyword breaks the intellisense functionality for that method

[Dragas]

The title is kind of verbose, but it summarizes the issue as best as possible. I run preference settings where I would attempt to deobfuscate anything that's less then 3 characters long (the default), so that I would afterwards rename the methods, variables, and etc. to proper names after figuring out what they're doing. In poor judgement, I had renamed a single method to assert, which corresponds to a keyword in java.

As a result, jad-gui now considers the method to be a keyword, and I am no longer able to perform any intellisense operations (such as find usages, rename, go to declaration) on that method, and any callers of that method.

In addition, the tool prevents reverting this action.

[Dragas]

Looking at the logs, they do not seem to provide anything besides the bad byte error.
https://pastebin.com/M8W6DbGN

[skylot]

@Dragas I add a check before rename to forbid not valid java identifiers.