What steps will reproduce the problem?

Run FindBugs GUI on the "mail" module of Project GlassFish (http://glassfish.dev.java.net).

There are several instances of code such as the following:

    if (message instanceof SMTPMessage)
        from = ((SMTPMessage)message).getEnvelopeFrom();

What is the expected output? What do you see instead?

Complains about an unchecked cast.

What version of the product are you using? On what operating system?

FindBugs 1.1.1, JDK 1.5.0_07, Solaris 10

Please provide any additional information below.

Darn, how do I fix the summary for this issue?

I need some more information to understand this report. Ideally, a sample Java file and an XML report generated by FindBugs.

Alternatively, just give me the specific file and line number within Glassfish where you are getting this false positive.

This occurs in com.sun.mail.smtp.SMTPTransport, in method mailFrom, about line 750: https://glassfish.dev.java.net/source/browse/glassfish/mail/src/java/com/sun/mail/smtp/SMTPTransport.java?view=markup It complains about the cast to SMTPMessage, even though it's checked with instanceof the line before.

Thanks for the report, but please report this bug at sourceforge bug tracker again. This tracker is not used / monitored.