fix: use soft checks for objects and arrays in 'if' type listener (#401)

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

@@ -518,6 +518,14 @@ public abstract class ArgType {
 		return false;
 	}
 
+	public boolean canBeObject() {
+		return isObject() || (!isTypeKnown() && contains(PrimitiveType.OBJECT));
+	}
+
+	public boolean canBeArray() {
+		return isArray() || (!isTypeKnown() && contains(PrimitiveType.ARRAY));
+	}
+
 	public static ArgType convertFromPrimitiveType(PrimitiveType primitiveType) {
 		switch (primitiveType) {
 			case BOOLEAN:

jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeUpdate.java

@@ -306,7 +306,18 @@ public final class TypeUpdate {
 		InsnArg firstArg = insn.getArg(0);
 		InsnArg secondArg = insn.getArg(1);
 		InsnArg updateArg = firstArg == arg ? secondArg : firstArg;
-		return updateTypeChecked(updateInfo, updateArg, candidateType);
+		TypeUpdateResult result = updateTypeChecked(updateInfo, updateArg, candidateType);
+		if (result == REJECT) {
+			// soft checks for objects and array - exact type not compared
+			ArgType updateArgType = updateArg.getType();
+			if (candidateType.isObject() && updateArgType.canBeObject()) {
+				return SAME;
+			}
+			if (candidateType.isArray() && updateArgType.canBeArray()) {
+				return SAME;
+			}
+		}
+		return result;
 	}
 
 	private static boolean isAssign(InsnNode insn, InsnArg arg) {

jadx-core/src/test/java/jadx/tests/integration/types/TestConstTypeInference.java

@@ -0,0 +1,64 @@
+package jadx.tests.integration.types;
+
+import org.junit.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.hamcrest.Matchers.anyOf;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertThat;
+
+public class TestConstTypeInference extends IntegrationTest {
+
+	public static class TestCls {
+		private final int a;
+
+		public TestCls() {
+			this(0);
+		}
+
+		public TestCls(int a) {
+			this.a = a;
+		}
+
+		public boolean equals(Object obj) {
+			if (obj == this) {
+				return true;
+			}
+			if (obj != null) {
+				if (getClass() == obj.getClass()) {
+					TestCls other = (TestCls) obj;
+					return this.a == other.a;
+				}
+			}
+			return false;
+		}
+
+		public void check() {
+			TestCls seven = new TestCls(7);
+			assertEquals(seven, seven);
+			assertNotEquals(seven, null);
+
+			TestCls six = new TestCls(6);
+			assertNotEquals(seven, six);
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsOne("obj == this"));
+		assertThat(code, anyOf(containsOne("obj == null"), containsOne("obj != null")));
+	}
+
+	@Test
+	public void test2() {
+		noDebugInfo();
+		getClassNode(TestCls.class);
+	}
+}