Description Daniel Lew 2007-08-06 12:38:26 EDT

If you turn Windows->Preferences->Java->Compiler->Errors/Warnings->UnnecessaryCode->"redundant null checks" to warning/error, you will get an erroneous error/warning on this code:

public static void foobar(String msg)
{
	StringBuffer buffer = null;
	int startIndex = 0;
	
	while (true) {
		int nextIndex = msg.indexOf('\n', startIndex);
		
		if (nextIndex < 0)
			break;
		
		if (buffer == null)
			buffer = new StringBuffer();
		
		startIndex = nextIndex + 1;
	}
	
	if (buffer == null)  // this shows up as a redundant null check
		System.out.println("Foobar");
}

It's true that buffer can be null, but depending on msg it can also be non-null, too.