fix: don't override type of method parameter in const deboxing (#723)

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

@@ -14,6 +14,7 @@ import jadx.core.dex.instructions.InvokeType;
 import jadx.core.dex.instructions.args.ArgType;
 import jadx.core.dex.instructions.args.InsnArg;
 import jadx.core.dex.instructions.args.RegisterArg;
+import jadx.core.dex.instructions.args.SSAVar;
 import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
@@ -90,14 +91,16 @@ public class DeboxingVisitor extends AbstractVisitor {
 		if (valueOfMths.contains(callMth)) {
 			RegisterArg resArg = insnNode.getResult();
 			InsnArg arg = insnNode.getArg(0);
-			if (arg.isLiteral() && checkArgUsage(resArg)) {
+			if (arg.isLiteral()) {
 				ArgType primitiveType = callMth.getArgumentsTypes().get(0);
 				ArgType boxType = callMth.getReturnType();
 				if (isNeedExplicitCast(resArg, primitiveType, boxType)) {
 					arg.add(AFlag.EXPLICIT_PRIMITIVE_TYPE);
 				}
-				resArg.setType(primitiveType);
 				arg.setType(primitiveType);
+				if (canChangeTypeToPrimitive(resArg)) {
+					resArg.setType(primitiveType);
+				}
 
 				InsnNode constInsn = new InsnNode(InsnType.CONST, 1);
 				constInsn.addArg(arg);
@@ -122,17 +125,23 @@ public class DeboxingVisitor extends AbstractVisitor {
 		return false;
 	}
 
-	private boolean checkArgUsage(RegisterArg arg) {
-		for (RegisterArg useArg : arg.getSVar().getUseList()) {
-			InsnNode parentInsn = useArg.getParentInsn();
-			if (parentInsn == null) {
+	private boolean canChangeTypeToPrimitive(RegisterArg arg) {
+		for (SSAVar ssaVar : arg.getSVar().getCodeVar().getSsaVars()) {
+			RegisterArg assignArg = ssaVar.getAssign();
+			if (assignArg.contains(AFlag.IMMUTABLE_TYPE)) {
 				return false;
 			}
-			if (parentInsn.getType() == InsnType.INVOKE) {
-				InvokeNode invokeNode = (InvokeNode) parentInsn;
-				if (useArg.equals(invokeNode.getInstanceArg())) {
+			for (RegisterArg useArg : ssaVar.getUseList()) {
+				InsnNode parentInsn = useArg.getParentInsn();
+				if (parentInsn == null) {
 					return false;
 				}
+				if (parentInsn.getType() == InsnType.INVOKE) {
+					InvokeNode invokeNode = (InvokeNode) parentInsn;
+					if (useArg.equals(invokeNode.getInstanceArg())) {
+						return false;
+					}
+				}
 			}
 		}
 		return true;

jadx-core/src/test/java/jadx/tests/integration/others/TestDeboxing2.java

@@ -0,0 +1,49 @@
+package jadx.tests.integration.others;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static jadx.tests.api.utils.JadxMatchers.countString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+
+public class TestDeboxing2 extends IntegrationTest {
+
+	public static class TestCls {
+		public long test(Long l) {
+			if (l == null) {
+				l = 0L;
+			}
+			return l;
+		}
+
+		public void check() {
+			assertThat(test(null), is(0L));
+			assertThat(test(0L), is(0L));
+			assertThat(test(7L), is(7L));
+		}
+	}
+
+	@Test
+	public void test() {
+		noDebugInfo();
+
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsOne("long test(Long l)"));
+		assertThat(code, containsOne("if (l == null) {"));
+		assertThat(code, containsOne("l = 0L;"));
+
+		// checks for 'check' method
+		assertThat(code, containsOne("test(null)"));
+		assertThat(code, containsOne("test(0L)"));
+		assertThat(code, countString(2, "is(0L)"));
+		assertThat(code, containsOne("test(7L)"));
+		assertThat(code, containsOne("is(7L)"));
+
+	}
+}

jadx-core/src/test/java/jadx/tests/integration/others/TestDeboxing3.java

@@ -0,0 +1,60 @@
+package jadx.tests.integration.others;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.NotYetImplemented;
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class TestDeboxing3 extends IntegrationTest {
+
+	public static class TestCls {
+
+		public static class Pair<F, S> {
+			public F first;
+			public S second;
+		}
+
+		private Map<String, Pair<Long, String>> cache = new HashMap<>();
+
+		public boolean test(String id, Long l) {
+			if (l == null) {
+				l = 900000L;
+			}
+			Pair<Long, String> pair = this.cache.get(id);
+			if (pair == null) {
+				return false;
+			}
+			return pair.first + l > System.currentTimeMillis();
+		}
+	}
+
+	@Test
+	public void test() {
+		noDebugInfo();
+
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsOne("l = 900000L;"));
+	}
+
+	@Test
+	@NotYetImplemented("Full deboxing and generics propagation")
+	public void testFull() {
+		noDebugInfo();
+
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsOne("Pair<Long, String> pair = this.cache.get(id);"));
+		assertThat(code, containsOne("return pair.first + l > System.currentTimeMillis();"));
+
+	}
+}