Bug 94367 cannot clear compiler compliance setting at the project level
i200505092010 Cannot disable the Java compiler project-specific preferences for some projects. Steps to reproduce: 1 - check out from CVS a Java project that has project-specific Java compiler settings enabled (example: org.eclipse.core.runtime). 2 - open the properties dialog for the project, select the Java compiler node, disable project-specific Java compiler preferences. 3 - Commit the changes by pressing "Ok" and reopen the properties dialog. It looks like the settings were not saved (project-specific settings are still enabled).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/OptionsConfigurationBlock.java
public boolean processChanges(boolean enabled, IWorkbenchPreferenceContainer container) {
		IScopeContext currContext= fLookupOrder[0];
	
		List  changedOptions= new ArrayList();
		boolean needsBuild= getChanges(currContext, enabled, changedOptions);
		if (changedOptions.isEmpty()) {
			return true;
		}
		
		boolean doBuild= false;
		if (needsBuild) {
			String[] strings= getFullBuildDialogStrings(fProject == null);
			if (strings != null) {
				MessageDialog dialog= new MessageDialog(getShell(), strings[0], null, strings[1], MessageDialog.QUESTION, new String[] { IDialogConstants.YES_LABEL, IDialogConstants.NO_LABEL, IDialogConstants.CANCEL_LABEL }, 2);
				int res= dialog.open();
				if (res == 0) {
					doBuild= true;
				} else if (res != 1) {
					return false; 
				}
			}
		}
		if (!enabled) {
			
			for (Iterator iter= changedOptions.iterator(); iter.hasNext();) {
				PropertyChange elem= (PropertyChange) iter.next();
				elem.key.setStoredValue(currContext, elem.newValue, fManager);
			}
		}
		if (container != null) {