fix: resolve duplicated error attr in fallback codegen, allow to set whole attr list at once (#2842)

jadx-core/src/main/java/jadx/core/codegen/MethodGen.java

@@ -397,13 +397,12 @@ public class MethodGen {
 				for (IDexTreeVisitor visitor : Jadx.getFallbackPassesList()) {
 					DepthTraversal.visit(visitor, mth);
 				}
-				errors.forEach(err -> mth.addAttr(AType.JADX_ERROR, err));
 			} catch (Exception e) {
 				LOG.error("Error reload instructions in fallback mode:", e);
 				code.startLine("// Can't load method instructions: " + e.getMessage());
 				return;
 			} finally {
-				errors.forEach(err -> mth.addAttr(AType.JADX_ERROR, err));
+				mth.addAttr(AType.JADX_ERROR, errors);
 			}
 		}
 		InsnNode[] insnArr = mth.getInstructions();

jadx-core/src/main/java/jadx/core/dex/attributes/AttrList.java

@@ -12,10 +12,16 @@ public class AttrList<T> implements IJadxAttribute {
 	private static final int MAX_ATTRLIST_LENGTH = 300;
 
 	private final IJadxAttrType<AttrList<T>> type;
-	private final List<T> list = new ArrayList<>();
+	private final List<T> list;
+
+	public AttrList(IJadxAttrType<AttrList<T>> type, List<T> attrList) {
+		this.type = type;
+		this.list = attrList;
+	}
 
 	public AttrList(IJadxAttrType<AttrList<T>> type) {
 		this.type = type;
+		this.list = new ArrayList<>();
 	}
 
 	public List<T> getList() {

jadx-core/src/main/java/jadx/core/dex/attributes/AttrNode.java

@@ -50,8 +50,7 @@ public abstract class AttrNode implements IAttributeNode {
 	}
 
 	public <T> void addAttr(IJadxAttrType<AttrList<T>> type, List<T> list) {
-		AttributeStorage strg = initStorage();
-		list.forEach(attr -> strg.add(type, attr));
+		initStorage().addAttrList(type, list);
 	}
 
 	@Override

jadx-core/src/main/java/jadx/core/dex/attributes/AttributeStorage.java

@@ -14,6 +14,7 @@ import jadx.api.plugins.input.data.attributes.IJadxAttrType;
 import jadx.api.plugins.input.data.attributes.IJadxAttribute;
 import jadx.api.plugins.input.data.attributes.JadxAttrType;
 import jadx.api.plugins.input.data.attributes.types.AnnotationsAttr;
+import jadx.core.utils.ListUtils;
 import jadx.core.utils.Utils;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
@@ -62,11 +63,20 @@ public class AttributeStorage {
 
 	public <T> void add(IJadxAttrType<AttrList<T>> type, T obj) {
 		AttrList<T> list = get(type);
-		if (list == null) {
-			list = new AttrList<>(type);
-			add(list);
+		if (list != null) {
+			list.getList().add(obj);
+		} else {
+			add(new AttrList<>(type, ListUtils.mutableListOf(obj)));
+		}
+	}
+
+	public <T> void addAttrList(IJadxAttrType<AttrList<T>> type, List<T> attrList) {
+		AttrList<T> list = get(type);
+		if (list != null) {
+			list.getList().addAll(attrList);
+		} else {
+			add(new AttrList<>(type, attrList));
 		}
-		list.getList().add(obj);
 	}
 
 	public void addAll(AttributeStorage otherList) {

jadx-core/src/main/java/jadx/core/utils/ListUtils.java

@@ -19,6 +19,25 @@ import org.jetbrains.annotations.Nullable;
 
 public class ListUtils {
 
+	public static <T> List<T> mutableListOf(T obj) {
+		List<T> list = new ArrayList<>();
+		list.add(obj);
+		return list;
+	}
+
+	public static <T> List<T> mutableListOf(T obj1, T obj2) {
+		List<T> list = new ArrayList<>();
+		list.add(obj1);
+		list.add(obj2);
+		return list;
+	}
+
+	public static <T> List<T> mutableListOf(T... objs) {
+		List<T> list = new ArrayList<>();
+		Collections.addAll(list, objs);
+		return list;
+	}
+
 	public static <T> boolean isSingleElement(@Nullable List<T> list, T obj) {
 		if (list == null || list.size() != 1) {
 			return false;