Keep the filter-chain consistent when using the LoggingTester

Manipulating the next-pointer of the linked list is error-prone
and corrupted the filter chain. It's safer to re-create the filter chain
from scratch by calling addFilter again.

Signed-off-by: Sebastian Zarnekow <[email protected]>

org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/logging/LoggingTester.java

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2015, 2022 itemis AG (http://www.itemis.eu) and others.
+ * Copyright (c) 2015, 2024 itemis AG (http://www.itemis.eu) and others.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0.
@@ -333,16 +333,18 @@ private static List<Appender> appenderHierarchy(Logger logger) {
 	}
 
 	private static void removeFilter(Appender appender, Filter filter) {
-		if (Objects.equal(appender.getFilter(), filter)) {
-			appender.clearFilters();
-			appender.addFilter(filter.getNext());
-		} else {
-			for (Filter current = appender.getFilter(); (current != null); current = current.getNext()) {
-				if (Objects.equal(current.getNext(), filter)) {
-					current.setNext(filter.getNext());
-					return;
-				}
+		List<Filter> filtersToKeep = new ArrayList<>();
+		Filter present = appender.getFilter();
+		while (present != null) {
+			if (!Objects.equal(present, filter)) {
+				filtersToKeep.add(present);
 			}
+			present = present.getNext();
+		}
+		appender.clearFilters();
+		for(Filter addMe: filtersToKeep) {
+			addMe.setNext(null);
+			appender.addFilter(addMe);
 		}
 	}
 

org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/logging/LoggingTester.java

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2015, 2020 itemis AG (http://www.itemis.eu) and others.
+ * Copyright (c) 2015, 2024 itemis AG (http://www.itemis.eu) and others.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0.
@@ -69,17 +69,19 @@ private static List<Appender> appenderHierarchy(Logger logger) {
 	}
 
 	private static void removeFilter(Appender appender, Filter filter) {
-		if (Objects.equals(appender.getFilter(), filter)) {
-			appender.clearFilters();
-			appender.addFilter(filter.getNext());
-		} else {
-			for (Filter current = appender.getFilter(); current != null; current = current.getNext()) {
-				if (Objects.equals(current.getNext(), filter)) {
-					current.setNext(filter.getNext());
-					return;
-				}
+		List<Filter> filtersToKeep = new ArrayList<>();
+		Filter present = appender.getFilter();
+		while (present != null) {
+			if (!Objects.equals(present, filter)) {
+				filtersToKeep.add(present);
 			}
+			present = present.getNext();
 		}
+		appender.clearFilters();
+		filtersToKeep.forEach(addMe -> {
+			addMe.setNext(null);
+			appender.addFilter(addMe);
+		});
 	}
 
 	public static class LogCapture {