Only replace text if found

MontiCore · Jan 1, 2025 · 984d0dc · 984d0dc
1 parent 82d7615
commit 984d0dc
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/monticore-runtime/src/main/java/de/monticore/antlr4/MCErrorListener.java b/monticore-runtime/src/main/java/de/monticore/antlr4/MCErrorListener.java
@@ -52,7 +52,9 @@ public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int
           // Due to our substitute-no-keyword handling, we remove no-keywords from the expected list (as they are included within Name)
           if (parser.getNoKeywordRuleNames() != null) {
             int index = msg.indexOf("' expecting "); // We strip everything after the expecting
-            msg = msg.substring(0, index) + "', expecting ";
+            if (index >= 0) {
+              msg = msg.substring(0, index) + "', expecting ";
+            }
 
             // Check for the rules which the ATN would change into using epsilon transitions (to find nokeywor rules)
             Set<Map.Entry<Integer, String>> epsilonRules = new HashSet<>();