Bug 5225 1.0 -- Casting problem in RunToLineAction class
The Java editor fails to open a java source file when we have PICLDebugTargets in the debug view. There is java.lang.ClassCastException at org.eclipse.jdt.internal.ui.javaeditor.RunToLineAction.getContextFromModel (RunToLineAction.java:111) The getContextFromModel() method incorrectly assumes that all debug targets are of type JDIDebugTarget. I see a few other spots in RunToLineAction where a debug target is blindly cast to a JDIDebugTarget without checking it first. I am seeing this with the R1.0 (0.137 build) driver. I don't think this is a new problem.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/RunToLineAction.java
/**
	 * @see IUpdate
	 */
	public void update() {
		try {
			setEnabled(getContext() != null);
		} catch (DebugException de) {
			setEnabled(false);
			JavaPlugin.log(de.getStatus());
		}
	}
	
	/**
	 * Resolves a stack frame context from the model
	 */
	protected JDIDebugTarget getContextFromDebugTarget(JDIDebugTarget dt) throws DebugException {
		if (dt.isTerminated() || dt.isDisconnected()) {
			return null;
		}
		IThread[] threads= dt.getThreads();
		for (int i= 0; i < threads.length; i++) {
			IThread thread= threads[i];
			if (thread.isSuspended()) {
				return dt;
			}
		}
		return null;
	}
}