Merge pull request #6291 from IllianiCBT/unitTableNullEmpty

Added Handling for When Unit Quality is Manually Set to Empty or `null` Quality

Author: IllianiBird

MekHQ/src/mekhq/gui/adapter/UnitTableMouseAdapter.java

@@ -219,6 +219,10 @@ public void actionPerformed(ActionEvent action) {
                     "Set Quality", JOptionPane.PLAIN_MESSAGE, null, possibilities,
                     PartQuality.QUALITY_D.toName(reverse));
 
+            if (quality == null || quality.isBlank()) {
+                return;
+            }
+
             PartQuality q = PartQuality.fromName(quality, reverse);
             for (Unit unit : units) {
                 if (null != unit) {