fix: replace type variables in arrays (#913)

jadx-core/src/main/java/jadx/core/dex/instructions/args/ArgType.java

@@ -5,6 +5,8 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
+import org.jetbrains.annotations.NotNull;
+
 import jadx.core.Consts;
 import jadx.core.dex.info.ClassInfo;
 import jadx.core.dex.nodes.ClassNode;
@@ -114,7 +116,7 @@ public abstract class ArgType {
 		return new OuterGenericObject((GenericObject) genericOuterType, (ObjectType) innerType);
 	}
 
-	public static ArgType array(ArgType vtype) {
+	public static ArgType array(@NotNull ArgType vtype) {
 		return new ArrayArg(vtype);
 	}
 

jadx-core/src/main/java/jadx/core/dex/nodes/utils/TypeUtils.java

@@ -117,6 +117,13 @@ public class TypeUtils {
 		if (replaceType.isGenericType()) {
 			return replaceMap.get(replaceType);
 		}
+		if (replaceType.isArray()) {
+			ArgType replaced = replaceTypeVariablesUsingMap(replaceType.getArrayElement(), replaceMap);
+			if (replaced == null) {
+				return null;
+			}
+			return ArgType.array(replaced);
+		}
 
 		ArgType wildcardType = replaceType.getWildcardType();
 		if (wildcardType != null && wildcardType.containsTypeVariable()) {

jadx-core/src/test/java/jadx/core/dex/nodes/utils/TypeUtilsTest.java

@@ -0,0 +1,45 @@
+package jadx.core.dex.nodes.utils;
+
+import java.util.Collections;
+import java.util.Map;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import jadx.api.JadxArgs;
+import jadx.core.dex.instructions.args.ArgType;
+import jadx.core.dex.nodes.RootNode;
+
+import static jadx.core.dex.instructions.args.ArgType.STRING;
+import static jadx.core.dex.instructions.args.ArgType.array;
+import static jadx.core.dex.instructions.args.ArgType.generic;
+import static jadx.core.dex.instructions.args.ArgType.genericType;
+import static jadx.core.dex.instructions.args.ArgType.object;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class TypeUtilsTest {
+	private TypeUtils typeUtils;
+
+	@BeforeEach
+	public void init() {
+		typeUtils = new TypeUtils(new RootNode(new JadxArgs()));
+	}
+
+	@Test
+	void replaceTypeVariablesUsingMap() {
+		ArgType typeVar = genericType("T");
+		ArgType listCls = object("java.util.List");
+		Map<ArgType, ArgType> typeMap = Collections.singletonMap(typeVar, STRING);
+
+		replaceTypeVar(typeVar, typeMap, STRING);
+		replaceTypeVar(generic(listCls, typeVar), typeMap, generic(listCls, STRING));
+		replaceTypeVar(array(typeVar), typeMap, array(STRING));
+	}
+
+	private void replaceTypeVar(ArgType typeVar, Map<ArgType, ArgType> typeMap, ArgType expected) {
+		ArgType resultType = typeUtils.replaceTypeVariablesUsingMap(typeVar, typeMap);
+		assertThat(resultType)
+				.as("Replace %s using map %s", typeVar, typeMap)
+				.isEqualTo(expected);
+	}
+}

jadx-core/src/test/java/jadx/tests/integration/generics/TestMethodOverride.java

@@ -15,6 +15,7 @@ public class TestMethodOverride extends SmaliTest {
 		assertThat(getClassNodeFromSmali())
 				.code()
 				.containsOne("String createFromParcel(Parcel parcel) {")
-				.containsOne("@Override");
+				.containsOne("String[] newArray(int i) {")
+				.countString(2, "@Override");
 	}
 }

jadx-core/src/test/smali/generics/TestMethodOverride.smali

@@ -36,3 +36,12 @@
     return-object v0
 .end method
 
+.method public final synthetic newArray(I)[Ljava/lang/Object;
+    .registers 2
+
+    .line 4
+    new-array p1, p1, [Ljava/lang/String;
+
+    return-object p1
+.end method
+