Bug 65399 changing a "Run a Single Test" configuration into "Run All Tests in..." does not run all tests [JUnit]
First I ran a single test (by selecting the test method and then choosing Run/JUnit Test from its context menu actions). Then I decided to run all tests in the package instead. So inside the Launching Configurations dialog I chose the option Run All Tests in selected project, package or folder and selected the package which contained the test class I had previously selected. Surprisingly it did not run all tests in the package I chose in the previous dialog, rather it ran only the same test from which I created that initial launching configuration. This is a bug which users are very likely to encounter: initially they will want to run a single test and then change their mind and try to run all tests within the corresponding package. 3.0 RC1 Build id: 200405290105
org.eclipse.jdt.junit/src/org/eclipse/jdt/internal/junit/launcher/JUnitMainTab.java
*/
	public boolean isValid(ILaunchConfiguration config) {		
		return getErrorMessage() == null;
	}
	
	private void testModeChanged() {
		boolean isSingleTestMode= fTestRadioButton.getSelection();
		setEnableSingleTestGroup(isSingleTestMode);
		setEnableContainerTestGroup(!isSingleTestMode);
		validatePage();
		updateLaunchConfigurationDialog();
	}
	private void validatePage() {
		setErrorMessage(null);
		setMessage(null);
		
		if (fTestContainerRadioButton.getSelection()) {
			if (fContainerElement == null)
				setErrorMessage(JUnitMessages.getString("JUnitMainTab.error.noContainer")); 
			return;
		} 
		
		String projectName = fProjText.getText().trim();
		if (projectName.length() == 0) {
			setErrorMessage(JUnitMessages.getString("JUnitMainTab.error.projectnotdefined")); 
			return;
		}
			
		IProject project = getWorkspaceRoot().getProject(projectName);
		if (!project.exists()) {