fix: use type from new-instance if differ from constructor call (#2285)

jadx-core/src/main/java/jadx/core/dex/instructions/mods/ConstructorInsn.java

@@ -25,8 +25,12 @@ public final class ConstructorInsn extends BaseInvokeNode {
 	}
 
 	public ConstructorInsn(MethodNode mth, InvokeNode invoke) {
+		this(mth, invoke, invoke.getCallMth());
+	}
+
+	public ConstructorInsn(MethodNode mth, InvokeNode invoke, MethodInfo callMth) {
 		super(InsnType.CONSTRUCTOR, invoke.getArgsCount() - 1);
-		this.callMth = invoke.getCallMth();
+		this.callMth = callMth;
 		this.callType = getCallType(mth, callMth.getDeclClass(), invoke.getArg(0));
 		int argsCount = invoke.getArgsCount();
 		for (int i = 1; i < argsCount; i++) {

jadx-core/src/main/java/jadx/core/dex/visitors/ConstructorVisitor.java

@@ -6,9 +6,13 @@ import org.jetbrains.annotations.Nullable;
 
 import jadx.core.codegen.TypeGen;
 import jadx.core.dex.attributes.AFlag;
+import jadx.core.dex.info.ClassInfo;
+import jadx.core.dex.info.MethodInfo;
+import jadx.core.dex.instructions.IndexInsnNode;
 import jadx.core.dex.instructions.InsnType;
 import jadx.core.dex.instructions.InvokeNode;
 import jadx.core.dex.instructions.PhiInsn;
+import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.LiteralArg;
 import jadx.core.dex.instructions.args.RegisterArg;
@@ -59,10 +63,17 @@ public class ConstructorVisitor extends AbstractVisitor {
 
 	private static boolean processInvoke(MethodNode mth, BlockNode block, int indexInBlock, InsnRemover remover) {
 		InvokeNode inv = (InvokeNode) block.getInstructions().get(indexInBlock);
-		if (!inv.getCallMth().isConstructor()) {
+		MethodInfo callMth = inv.getCallMth();
+		if (!callMth.isConstructor()) {
 			return false;
 		}
-		ConstructorInsn co = new ConstructorInsn(mth, inv);
+		ArgType instType = searchInstanceType(inv);
+		if (instType != null && !instType.equals(callMth.getDeclClass().getType())) {
+			ClassInfo instCls = ClassInfo.fromType(mth.root(), instType);
+			callMth = MethodInfo.fromDetails(mth.root(), instCls, callMth.getName(),
+					callMth.getArgumentsTypes(), callMth.getReturnType());
+		}
+		ConstructorInsn co = new ConstructorInsn(mth, inv, callMth);
 		if (canRemoveConstructor(mth, co)) {
 			remover.addAndUnbind(inv);
 			return false;
@@ -101,6 +112,18 @@ public class ConstructorVisitor extends AbstractVisitor {
 		return true;
 	}
 
+	private static @Nullable ArgType searchInstanceType(InvokeNode inv) {
+		InsnArg instanceArg = inv.getInstanceArg();
+		if (instanceArg == null || !instanceArg.isRegister()) {
+			return null;
+		}
+		InsnNode assignInsn = ((RegisterArg) instanceArg).getSVar().getAssignInsn();
+		if (assignInsn == null || assignInsn.getType() != InsnType.NEW_INSTANCE) {
+			return null;
+		}
+		return ((IndexInsnNode) assignInsn).getIndexAsType();
+	}
+
 	private static RegisterArg insertPhiInsn(MethodNode mth, BlockNode curBlock,
 			RegisterArg instArg, ConstructorInsn otherCtr) {
 		BlockNode otherBlock = BlockUtils.getBlockByInsn(mth, otherCtr);

jadx-core/src/test/java/jadx/tests/integration/others/TestConstructor2.java

@@ -0,0 +1,20 @@
+package jadx.tests.integration.others;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+/**
+ * Constructor called on object instance is from Object not instance type
+ */
+public class TestConstructor2 extends SmaliTest {
+
+	@Test
+	public void test() {
+		assertThat(getClassNodeFromSmaliFiles())
+				.code()
+				.containsOne("A a = new A();");
+	}
+}

jadx-core/src/test/smali/others/TestConstructor2/A.smali

@@ -0,0 +1,5 @@
+.class public final Lothers/TestConstructor2$A;
+.super Ljava/lang/Object;
+
+.field public a:I
+.field public b:Ljava/util/ArrayDeque;

jadx-core/src/test/smali/others/TestConstructor2/TestConstructor2.smali

@@ -0,0 +1,79 @@
+.class public Lothers/TestConstructor2;
+.super Ljava/lang/Object;
+
+.field public a:Ljava/util/HashMap;
+
+.method public final a(III)V
+    .registers 6
+
+    .line 1
+    .line 2
+    new-instance v0, Lothers/TestConstructor2$A;
+
+    .line 3
+    .line 4
+    .line 5
+    invoke-direct {v0}, Ljava/lang/Object;-><init>()V
+
+    .line 6
+    .line 7
+    if-gt p2, p3, :cond_1c
+
+    .line 8
+    .line 9
+    new-instance p2, Ljava/util/ArrayDeque;
+
+    .line 10
+    .line 11
+    iget v1, v0, Lothers/TestConstructor2$A;->a:I
+
+    .line 12
+    .line 13
+    .line 14
+    invoke-direct {p2, v1}, Ljava/util/ArrayDeque;-><init>(I)V
+
+    .line 15
+    .line 16
+    iput-object p2, v0, Lothers/TestConstructor2$A;->b:Ljava/util/ArrayDeque;
+
+    .line 17
+    .line 18
+    iput p3, v0, Lothers/TestConstructor2$A;->a:I
+
+    .line 19
+    .line 20
+    iget-object p2, p0, Lothers/TestConstructor2;->a:Ljava/util/HashMap;
+
+    .line 21
+    .line 22
+    .line 23
+    invoke-static {p1}, Ljava/lang/Integer;->valueOf(I)Ljava/lang/Integer;
+
+    .line 24
+    move-result-object p1
+
+    .line 25
+    .line 26
+    .line 27
+    invoke-virtual {p2, p1, v0}, Ljava/util/HashMap;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
+
+    .line 28
+    return-void
+
+    .line 29
+    .line 30
+    :cond_1c
+    new-instance p1, Ljava/lang/IllegalArgumentException;
+
+    .line 31
+    .line 32
+    const-string/jumbo p2, "error"
+
+    .line 33
+    .line 34
+    .line 35
+    invoke-direct {p1, p2}, Ljava/lang/IllegalArgumentException;-><init>(Ljava/lang/String;)V
+
+    .line 36
+    throw p1
+.end method