Created attachment 53804 [details] [review]
A patch to prevent the JVM crash

This patch will replace a null fileName with the empty string.

The current behaviour is definitely not acceptable, but I am not sure if the
proposed behaviour is the right way to go. How about the possibility of throwing
an exception?

At first I was thinking of throwing a runtime exception, but then I took a look
at Entry.setText() as a reference and I noticed that it was changing the input
parameter. Therefore, I did the same assuming that it will be the right thing.

I agree that modifying the input parameters can be tricky, in this case changing
from null to the empty string can be understood but in other cases it may not be
as trivial.

Personally I will prefer the API to be consistent. Either all methods validate
their input and throw a runtime exception (possibly the same) or have them
modify the input value in order to correct it, as it is done by Entry.setText().

I am open to all suggestions as long we can prevent the JVM from crashing and
that the errors can be trapped or prevented by java code.

Unfortunately, the bindings are not very consistent. I am of the opinion that
setter methods should throw an IllegalArgumentException if they are passed null
in cases where null is not an acceptable value. In the case of Entry#setText,
the documentation does not mention if null values are acceptable, but I wonder
if people are relying on that behaviour already...

Do you mind then updating the code of FileChooserButton#setFilename with a
runtime exception or should I resubmit another patch?

I can do it. Also the correct way to do this is to have the check in
FileChooserHelper so that the various FileChooser implementations can benefit
from the check. I first wanted to know if the RuntimeException was satisfactory
to you, however.

The runtime exception works for me and modifying FileChooserHelper is a great idea.

Thanks for reporting this. Fixed all FileChooser implementations
(FileChooserDialog, FileChooserButton, FileChooserWidget) in CVS HEAD.