Bug 137073 [Preferences] Encoding field editor never fires value change events
The class AbstractEncodingFieldEditor never fires VALUE property change events unless the validaty of the value has also changed. I will attach a patch that corrects the problem.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
* @param selectedEncoding
	 *            the selected encoding, or <code>null</code>
	 */
	private void populateEncodingsCombo(List encodings, String selectedEncoding) {
		String[] encodingStrings = new String[encodings.size()];
		encodings.toArray(encodingStrings);
		encodingCombo.setItems(encodingStrings);
		if (selectedEncoding == null) {
			encodingCombo.setText(getDefaultEnc());
		} else {
			encodingCombo.setText(selectedEncoding);
		}
	}
	private void updateEncodingState(boolean useDefault) {
		defaultEncodingButton.setSelection(useDefault);
		otherEncodingButton.setSelection(!useDefault);
		if (useDefault) {
			encodingCombo.setText(getDefaultEnc());
		}
		encodingCombo.setEnabled(!useDefault);
		setPresentsDefaultValue(useDefault);
		updateValidState();
	}
	private void updateValidState() {
		boolean isValidNow = isEncodingValid();
		if (isValidNow != isValid) {
			isValid = isValidNow;
			if (isValid) {
				clearErrorMessage();
			} else {